Document:

<PAGE>

                                                                     Exhibit 4.2

                                                                       EXHIBIT A

                          REGISTRATION RIGHTS AGREEMENT

          This Registration Rights Agreement (this "Agreement") is made and
entered into as of July 17, 2006, among Alfacell Corporation, a Delaware
corporation (the "Company"), and the several purchasers signatory hereto (each
such purchaser is a "Purchaser" and collectively, the "Purchasers").

          This Agreement is made pursuant to the Securities Purchase Agreement,
dated as of the date hereof between the Company and each Purchaser (the
"Purchase Agreement").

          The Company and each Purchaser hereby agrees as follows:

     1. Definitions. Capitalized terms used and not otherwise defined herein
that are defined in the Purchase Agreement shall have the meanings given such
terms in the Purchase Agreement. As used in this Agreement, the following terms
shall have the following meanings:

          "Advice" shall have the meaning set forth in Section 6(d).

          "Effectiveness Date" means, with respect to the initial Registration
     Statement required to be filed hereunder, the 90th calendar day following
     the date hereof (the 120th calendar day in the case of a "review;"
     provided, however, in the event the Company is notified by the Commission
     that one of the above Registration Statements will not be reviewed or is no
     longer subject to further review and comments, the Effectiveness Date as to
     such Registration Statement shall be the fifth Trading Day following the
     date on which the Company is so notified if such date precedes the dates
     required above.

          "Effectiveness Period" shall have the meaning set forth in Section
     2(a).

          "Event" shall have the meaning set forth in Section 2(b).

          "Event Date" shall have the meaning set forth in Section 2(b).

          "Filing Date" means, with respect to the initial Registration
     Statement required hereunder, the 45th calendar day following the date
     hereof.

          "Holder" or "Holders" means the holder or holders, as the case may be,
     from time to time of Registrable Securities.

          "Indemnified Party" shall have the meaning set forth in Section 5(c).

          "Indemnifying Party" shall have the meaning set forth in Section 5(c).

          "Losses" shall have the meaning set forth in Section 5(a).

          "Plan of Distribution" shall have the meaning set forth in Section
     2(a).

                                       1

<PAGE>

          "Prospectus" means the prospectus included in a Registration Statement
     (including, without limitation, a prospectus that includes any information
     previously omitted from a prospectus filed as part of an effective
     registration statement in reliance upon Rule 430A promulgated under the
     Securities Act), as amended or supplemented by any prospectus supplement,
     with respect to the terms of the offering of any portion of the Registrable
     Securities covered by a Registration Statement, and all other amendments
     and supplements to the Prospectus, including post-effective amendments, and
     all material incorporated by reference or deemed to be incorporated by
     reference in such Prospectus.

          "Registrable Securities" means all of (i) the Shares issuable, (ii)
     the Warrant Shares issuable, (iii) any additional shares issuable in
     connection with any anti-dilution provisions in the Warrants (without
     giving effect to any limitations on exercise set forth in the Warrant) and
     (iv) any shares of Common Stock issued or issuable upon any stock split,
     dividend or other distribution, recapitalization or similar event with
     respect to the foregoing.

          "Registration Statement" means the registration statements required to
     be filed hereunder including (in each case) the Prospectus, amendments and
     supplements to such registration statement or Prospectus, including pre-
     and post-effective amendments, all exhibits thereto, and all material
     incorporated by reference or deemed to be incorporated by reference in such
     registration statement.

          "Rule 415" means Rule 415 promulgated by the Commission pursuant to
     the Securities Act, as such Rule may be amended from time to time, or any
     similar rule or regulation hereafter adopted by the Commission having
     substantially the same purpose and effect as such Rule.

          "Rule 424" means Rule 424 promulgated by the Commission pursuant to
     the Securities Act, as such Rule may be amended from time to time, or any
     similar rule or regulation hereafter adopted by the Commission having
     substantially the same purpose and effect as such Rule.

          "Selling Shareholder Questionnaire" shall have the meaning set forth
     in Section 3(a).

     2. Shelf Registration.

          (a) On or prior to each Filing Date, the Company shall prepare and
     file with the Commission a "Shelf" Registration Statement covering the
     resale of 100% of the Registrable Securities on such Filing Date for an
     offering to be made on a continuous basis pursuant to Rule 415. The
     Registration Statement shall be on Form S-3 (except if the Company is not
     then eligible to register for resale the Registrable Securities on Form
     S-3, in which case such registration shall be on another appropriate form
     in accordance herewith) and shall contain (unless otherwise directed by at
     least an 85% majority in interest of the Holders) substantially the "Plan
     of Distribution" attached hereto as Annex A. Subject to the terms of this
     Agreement, the Company shall use its best efforts to cause a Registration
     Statement to be declared effective under the Securities Act as promptly as

                                       2

<PAGE>

     possible after the filing thereof, but in any event prior to the applicable
     Effectiveness Date, and shall use its best efforts to keep such
     Registration Statement continuously effective under the Securities Act
     until all Registrable Securities covered by such Registration Statement
     have been sold, or may be sold without volume restrictions pursuant to Rule
     144(k), as determined by the counsel to the Company pursuant to a written
     opinion letter to such effect, addressed and acceptable to the Company's
     transfer agent and the affected Holders (the "Effectiveness Period"). The
     Company shall telephonically request effectiveness of a Registration
     Statement as of 5:00 pm Eastern Time on a Trading Day. The Company shall
     immediately notify the Holders via facsimile or e-mail of the effectiveness
     of a Registration Statement on the same Trading Day that the Company
     telephonically confirms effectiveness with the Commission, which shall be
     the date requested for effectiveness of a Registration Statement. The
     Company shall, by 9:30 am Eastern Time on the Trading Day after the
     Effective Date (as defined in the Purchase Agreement), file a final
     Prospectus with the Commission pursuant to Rule 424. Failure to so notify
     the Holder within 1 Trading Day of such notification or effectiveness or
     failure to file a final Prospectus as aforesaid shall be deemed an Event
     under Section 2(b).

          (b) If: (i) a Registration Statement is not filed on or prior to its
     Filing Date (if the Company files a Registration Statement without
     affording the Holders the opportunity to review and comment on the same as
     required by Section 3(a), the Company shall not be deemed to have satisfied
     this clause (i)), or (ii) the Company fails to file with the Commission a
     request for acceleration in accordance with Rule 461 promulgated under the
     Securities Act, within seven Trading Days of the date that the Company is
     notified (orally or in writing, whichever is earlier) by the Commission
     that a Registration Statement will not be "reviewed," or not subject to
     further review, or (iii) prior to its Effectiveness Date, the Company fails
     to file a pre-effective amendment and otherwise respond in writing to
     comments made by the Commission in respect of such Registration Statement
     within 20 calendar days after the receipt of comments by or notice from the
     Commission that such amendment is required in order for a Registration
     Statement to be declared effective, or (iv) a Registration Statement filed
     or required to be filed hereunder is not declared effective by the
     Commission by its Effectiveness Date, or (v) after the Effectiveness Date,
     a Registration Statement ceases for any reason to remain continuously
     effective as to all Registrable Securities for which it is required to be
     effective, or the Holders are otherwise not permitted to utilize the
     Prospectus therein to resell such Registrable Securities for more than 15
     consecutive calendar days or more than an aggregate of 25 calendar days
     during any 12-month period (which need not be consecutive calendar days)
     (any such failure or breach being referred to as an "Event", and for
     purposes of clause (i) or (iv) the date on which such Event occurs, or for
     purposes of clause (ii) the date on which such seven Trading Day period is
     exceeded, or for purposes of clause (iii) the date which such 20 calendar
     day period is exceeded, or for purposes of clause (v) the date on which
     such 15 or 25 calendar day period, as applicable, is exceeded being
     referred to as "Event Date"), then in addition to any other rights the
     Holders may have hereunder or under applicable law, on each such Event Date
     and on each monthly anniversary of each such Event Date (if the applicable
     Event shall not have been cured by such date) until the applicable Event is
     cured, the Company shall pay to each Holder an amount in cash, as partial
     liquidated damages and not as a penalty, equal

                                       3

<PAGE>

     to 2% of the aggregate purchase price paid by such Holder pursuant to the
     Purchase Agreement for any Registrable Securities then held by such Holder;
     provided that the Company shall not be required to pay partial liquidated
     damages to such Holder in excess of 10% of such Holder's purchase price
     under the Purchase Agreement. If the Company fails to pay any partial
     liquidated damages pursuant to this Section in full within seven days after
     the date payable, the Company will pay interest thereon at a rate of 18%
     per annum (or such lesser maximum amount that is permitted to be paid by
     applicable law) to the Holder, accruing daily from the date such partial
     liquidated damages are due until such amounts, plus all such interest
     thereon, are paid in full. The partial liquidated damages pursuant to the
     terms hereof shall apply on a daily pro-rata basis for any portion of a
     month prior to the cure of an Event.

     3. Registration Procedures

          In connection with the Company's registration obligations hereunder,
the Company shall:

          (a) Not less than five Trading Days prior to the filing of each
     Registration Statement and not less than 1 Trading Day prior to the filing
     of any related Prospectus or any amendment or supplement thereto, the
     Company shall, (i) furnish to each Holder copies of all such documents
     proposed to be filed, which documents (other than those incorporated or
     deemed to be incorporated by reference) will be subject to the review of
     such Holders. The Company shall not file a Registration Statement or any
     such Prospectus or any amendments or supplements thereto to which the
     Holders of a majority of the Registrable Securities shall reasonably object
     in good faith, provided that, the Company is notified of such objection in
     writing no later than 5 Trading Days after the Holders have been so
     furnished copies of a Registration Statement or 1 Trading Day after the
     Holders have been so furnished copies of any related Prospectus or
     amendment or supplement thereto. Each Holder agrees to furnish to the
     Company a completed Questionnaire in the form attached to this Agreement as
     Annex B (a "Selling Shareholder Questionnaire") not less than two Trading
     Days prior to the Filing Date or by the end of the fourth Trading Day
     following the date on which such Holder receives draft materials in
     accordance with this Section.

          (b) (i) Prepare and file with the Commission such amendments,
     including post-effective amendments, to a Registration Statement and the
     Prospectus used in connection therewith as may be necessary to keep a
     Registration Statement continuously effective as to the applicable
     Registrable Securities for the Effectiveness Period and prepare and file
     with the Commission such additional Registration Statements in order to
     register for resale under the Securities Act all of the Registrable
     Securities; (ii) cause the related Prospectus to be amended or supplemented
     by any required Prospectus supplement (subject to the terms of this
     Agreement), and as so supplemented or amended to be filed pursuant to Rule
     424; (iii) respond as promptly as reasonably possible to any comments
     received from the Commission with respect to a Registration Statement or
     any amendment thereto and as promptly as reasonably possible provide the
     Holders true and complete copies of all correspondence from and to the
     Commission relating to a Registration Statement (provided that the Company
     may excise any information

                                       4

<PAGE>

     contained therein which would constitute material non-public information as
     to any Holder which has not executed a confidentiality agreement with the
     Company); and (iv) comply in all material respects with the provisions of
     the Securities Act and the Exchange Act with respect to the disposition of
     all Registrable Securities covered by a Registration Statement during the
     applicable period in accordance (subject to the terms of this Agreement)
     with the intended methods of disposition by the Holders thereof set forth
     in such Registration Statement as so amended or in such Prospectus as so
     supplemented.

          (c) Notify the Holders of Registrable Securities to be sold (which
     notice shall, pursuant to clauses (iii) through (vi) hereof, be accompanied
     by an instruction to suspend the use of the Prospectus until the requisite
     changes have been made) as promptly as reasonably possible (and, in the
     case of (i)(A) below, not less than 1 Trading Day prior to such filing) and
     (if requested by any such Person) confirm such notice in writing no later
     than one Trading Day following the day (i)(A) when a Prospectus or any
     Prospectus supplement or post-effective amendment to a Registration
     Statement is proposed to be filed; (B) when the Commission notifies the
     Company whether there will be a "review" of such Registration Statement and
     whenever the Commission comments in writing on such Registration Statement;
     and (C) with respect to a Registration Statement or any post-effective
     amendment, when the same has become effective; (ii) of any request by the
     Commission or any other Federal or state governmental authority for
     amendments or supplements to a Registration Statement or Prospectus or for
     additional information; (iii) of the issuance by the Commission or any
     other federal or state governmental authority of any stop order suspending
     the effectiveness of a Registration Statement covering any or all of the
     Registrable Securities or the initiation of any Proceedings for that
     purpose; (iv) of the receipt by the Company of any notification with
     respect to the suspension of the qualification or exemption from
     qualification of any of the Registrable Securities for sale in any
     jurisdiction, or the initiation or threatening of any Proceeding for such
     purpose; (v) of the occurrence of any event or passage of time that makes
     the financial statements included in a Registration Statement ineligible
     for inclusion therein or any statement made in a Registration Statement or
     Prospectus or any document incorporated or deemed to be incorporated
     therein by reference untrue in any material respect or that requires any
     revisions to a Registration Statement, Prospectus or other documents so
     that, in the case of a Registration Statement or the Prospectus, as the
     case may be, it will not contain any untrue statement of a material fact or
     omit to state any material fact required to be stated therein or necessary
     to make the statements therein, in light of the circumstances under which
     they were made, not misleading; and (vi) the occurrence or existence of any
     pending corporate development with respect to the Company that the Company
     believes may be material and that, in the determination of the Company,
     makes it not in the best interest of the Company to allow continued
     availability of a Registration Statement or Prospectus; provided that any
     and all of such information shall remain confidential to each Holder until
     such information otherwise becomes public, unless disclosure by a Holder is
     required by law; provided, further, notwithstanding each Holder's agreement
     to keep such information confidential, the Holders make no acknowledgement
     that any such information is material, non-public information.

          (d) Use its best efforts to avoid the issuance of, or, if issued,
     obtain the withdrawal of (i) any order suspending the effectiveness of a
     Registration Statement, or

                                       5

<PAGE>

     (ii) any suspension of the qualification (or exemption from qualification)
     of any of the Registrable Securities for sale in any jurisdiction, at the
     earliest practicable moment.

          (e) Furnish to each Holder, without charge, at least one conformed
     copy of each such Registration Statement and each amendment thereto, and if
     requested in writing by a Holder, financial statements and schedules to the
     Registration Statement, all documents incorporated or deemed to be
     incorporated therein by reference to the extent requested by such Person,
     and all exhibits to the extent requested by such Person (including those
     previously furnished or incorporated by reference) promptly after the
     filing of such documents with the Commission.

          (f) Subject to the terms of this Agreement, the Company hereby
     consents to the use of such Prospectus and each amendment or supplement
     thereto by each of the selling Holders in connection with the offering and
     sale of the Registrable Securities covered by such Prospectus and any
     amendment or supplement thereto, except after the giving of any notice
     pursuant to Section 3(d).

          (g) If NASDR Rule 2710 requires any broker-dealer to make a filing
     prior to executing a sale by a Holder, the Company shall (i) make an Issuer
     Filing with the NASDR, Inc. Corporate Financing Department pursuant to
     proposed NASDR Rule 2710(b)(10)(A)(i), (ii) respond within five Trading
     Days to any comments received from NASDR in connection therewith, and (iii)
     pay the filing fee required in connection therewith.

          (h) Prior to any resale of Registrable Securities by a Holder, use its
     commercially reasonable efforts to register or qualify or cooperate with
     the selling Holders in connection with the registration or qualification
     (or exemption from the Registration or qualification) of such Registrable
     Securities for the resale by the Holder under the securities or Blue Sky
     laws of such jurisdictions within the United States as any Holder
     reasonably requests in writing, to keep each registration or qualification
     (or exemption therefrom) effective during the Effectiveness Period and to
     do any and all other acts or things reasonably necessary to enable the
     disposition in such jurisdictions of the Registrable Securities covered by
     each Registration Statement; provided, that the Company shall not be
     required to qualify generally to do business in any jurisdiction where it
     is not then so qualified, subject the Company to any material tax in any
     such jurisdiction where it is not then so subject or file a general consent
     to service of process in any such jurisdiction.

          (i) If requested by the Holders, cooperate with the Holders to
     facilitate the timely preparation and delivery of certificates representing
     Registrable Securities to be delivered to a transferee pursuant to a
     Registration Statement, which certificates shall be free, to the extent
     permitted by the Purchase Agreement, of all restrictive legends, and to
     enable such Registrable Securities to be in such denominations and
     registered in such names as any such Holders may request.

          (j) Upon the occurrence of any event contemplated by this Section 3,
     as promptly as reasonably possible under the circumstances taking into
     account the

                                       6

<PAGE>

     Company's good faith assessment of any adverse consequences to the Company
     and its stockholders of the premature disclosure of such event, prepare a
     supplement or amendment, including a post-effective amendment, to a
     Registration Statement or a supplement to the related Prospectus or any
     document incorporated or deemed to be incorporated therein by reference,
     and file any other required document so that, as thereafter delivered,
     neither a Registration Statement nor such Prospectus will contain an untrue
     statement of a material fact or omit to state a material fact required to
     be stated therein or necessary to make the statements therein, in light of
     the circumstances under which they were made, not misleading. If the
     Company notifies the Holders in accordance with clauses (iii) through (vi)
     of Section 3(d) above to suspend the use of any Prospectus until the
     requisite changes to such Prospectus have been made, then the Holders shall
     suspend use of such Prospectus. The Company will use its best efforts to
     ensure that the use of the Prospectus may be resumed as promptly as is
     practicable. The Company shall be entitled to exercise its right under this
     Section 3(k) to suspend the availability of a Registration Statement and
     Prospectus, subject to the payment of partial liquidated damages pursuant
     to Section 2(b), for a period not to exceed 60 calendar days (which need
     not be consecutive days) in any 12 month period.

          (k) Comply with all applicable rules and regulations of the
     Commission.

          (l) The Company may require each selling Holder to furnish to the
     Company a certified statement as to the number of shares of Common Stock
     beneficially owned by such Holder and, if required by the Commission, the
     natural persons thereof that have voting and dispositive control over the
     Shares. During any periods that the Company is unable to meet its
     obligations hereunder with respect to the registration of the Registrable
     Securities solely because any Holder fails to furnish such information
     within three Trading Days of the Company's request, any liquidated damages
     that are accruing at such time as to such Holder only shall be tolled and
     any Event that may otherwise occur solely because of such delay shall be
     suspended as to such Holder only, until such information is delivered to
     the Company.

     4. Registration Expenses. All fees and expenses incident to the performance
of or compliance with this Agreement by the Company shall be borne by the
Company whether or not any Registrable Securities are sold pursuant to a
Registration Statement. The fees and expenses referred to in the foregoing
sentence shall include, without limitation, (i) all registration and filing fees
(including, without limitation, fees and expenses (A) with respect to filings
required to be made with any Trading Market on which the Common Stock is then
listed for trading, (B) in compliance with applicable state securities or Blue
Sky laws reasonably agreed to by the Company in writing (including, without
limitation, fees and disbursements of counsel for the Company in connection with
Blue Sky qualifications or exemptions of the Registrable Securities) and (C) if
not previously paid by the Company in connection with an Issuer Filing, with
respect to any filing that may be required to be made by any broker through
which a Holder intends to make sales of Registrable Securities with NASD
Regulation, Inc. pursuant to the NASD Rule 2710, so long as the broker is
receiving no more than a customary brokerage commission in connection with such
sale, (ii) printing expenses (including, without limitation, expenses of
printing certificates for Registrable Securities, (iii) messenger, telephone and
delivery expenses, (iv) fees and disbursements of counsel for the Company, (v)
Securities Act

                                       7

<PAGE>

liability insurance, if the Company so desires such insurance, and (vi) fees and
expenses of all other Persons retained by the Company in connection with the
consummation of the transactions contemplated by this Agreement. In addition,
the Company shall be responsible for all of its internal expenses incurred in
connection with the consummation of the transactions contemplated by this
Agreement (including, without limitation, all salaries and expenses of its
officers and employees performing legal or accounting duties), the expense of
any annual audit and the fees and expenses incurred in connection with the
listing of the Registrable Securities on any securities exchange as required
hereunder. In no event shall the Company be responsible for any broker or
similar commissions of any Holder or, except to the extent provided for in the
Transaction Documents, any legal fees or other costs of the Holders.

     5. Indemnification

          (a) Indemnification by the Company. The Company shall, notwithstanding
     any termination of this Agreement, indemnify and hold harmless each Holder,
     the officers, directors, members, partners, agents, brokers (including
     brokers who offer and sell Registrable Securities as principal as a result
     of a pledge or any failure to perform under a margin call of Common Stock),
     investment advisors and employees (and any other Persons with a
     functionally equivalent role of a Person holding such titles,
     notwithstanding a lack of such title or any other title) of each of them,
     each Person who controls any such Holder (within the meaning of Section 15
     of the Securities Act or Section 20 of the Exchange Act) and the officers,
     directors, members, shareholders, partners, agents and employees (and any
     other Persons with a functionally equivalent role of a Person holding such
     titles, notwithstanding a lack of such title or any other title)of each
     such controlling Person, to the fullest extent permitted by applicable law,
     from and against any and all losses, claims, damages, liabilities, costs
     (including, without limitation, reasonable attorneys' fees) and expenses
     (collectively, "Losses"), as incurred, arising out of or relating to (1)
     any untrue or alleged untrue statement of a material fact contained in a
     Registration Statement, any Prospectus or any form of prospectus or in any
     amendment or supplement thereto or in any preliminary prospectus, or
     arising out of or relating to any omission or alleged omission of a
     material fact required to be stated therein or necessary to make the
     statements therein (in the case of any Prospectus or form of prospectus or
     supplement thereto, in light of the circumstances under which they were
     made) not misleading, or (2) any violation or alleged violation by the
     Company of the Securities Act, Exchange Act or any state securities law, or
     any rule or regulation thereunder, in connection with the performance of
     its obligations under this Agreement, except to the extent, but only to the
     extent, that (i) such untrue statements or omissions are based solely upon
     information regarding such Holder furnished in writing to the Company by
     such Holder expressly for use therein, or to the extent that such
     information relates to such Holder or such Holder's proposed method of
     distribution of Registrable Securities and was reviewed and expressly
     approved in writing by such Holder expressly for use in a Registration
     Statement, such Prospectus or such form of Prospectus or in any amendment
     or supplement thereto (it being understood that the Holder has approved
     Annex A hereto for this purpose) or (ii) in the case of an occurrence of an
     event of the type specified in Section 3(d)(iii)-(vi), the use by such
     Holder of an outdated or defective Prospectus after the Company has
     notified such Holder in writing that the Prospectus is outdated or
     defective and prior to the receipt by such Holder of the Advice
     contemplated

                                       8

<PAGE>

     in Section 6(d). The Company shall notify the Holders promptly of the
     institution, threat or assertion of any Proceeding arising from or in
     connection with the transactions contemplated by this Agreement of which
     the Company is aware.

          (b) Indemnification by Holders. Each Holder shall, severally and not
     jointly, indemnify and hold harmless the Company, its directors, officers,
     agents and employees, each Person who controls the Company (within the
     meaning of Section 15 of the Securities Act and Section 20 of the Exchange
     Act), and the directors, officers, agents or employees of such controlling
     Persons, to the fullest extent permitted by applicable law, from and
     against all Losses, as incurred, to the extent arising out of or based
     solely upon: (x) such Holder's failure to comply with the prospectus
     delivery requirements of the Securities Act or (y) any untrue or alleged
     untrue statement of a material fact contained in any Registration
     Statement, any Prospectus, or any form of prospectus, or in any amendment
     or supplement thereto or in any preliminary prospectus, or arising out of
     or relating to any omission or alleged omission of a material fact required
     to be stated therein or necessary to make the statements therein not
     misleading (i) to the extent, but only to the extent, that such untrue
     statement or omission is contained in any information so furnished in
     writing by such Holder to the Company specifically for inclusion in such
     Registration Statement or such Prospectus or (ii) to the extent that such
     information relates to such Holder's proposed method of distribution of
     Registrable Securities and was reviewed and expressly approved in writing
     by such Holder expressly for use in a Registration Statement (it being
     understood that the Holder has approved Annex A hereto for this purpose),
     such Prospectus or such form of Prospectus or in any amendment or
     supplement thereto or (iii) in the case of an occurrence of an event of the
     type specified in Section 3(d)(iii)-(vi), the use by such Holder of an
     outdated or defective Prospectus after the Company has notified such Holder
     in writing that the Prospectus is outdated or defective and prior to the
     receipt by such Holder of the Advice contemplated in Section 6(d). In no
     event shall the liability of any selling Holder hereunder be greater in
     amount than the dollar amount of the net proceeds received by such Holder
     upon the sale of the Registrable Securities giving rise to such
     indemnification obligation.

          (c) Conduct of Indemnification Proceedings. If any Proceeding shall be
     brought or asserted against any Person entitled to indemnity hereunder (an
     "Indemnified Party"), such Indemnified Party shall promptly notify the
     Person from whom indemnity is sought (the "Indemnifying Party") in writing,
     and the Indemnifying Party shall have the right to assume the defense
     thereof, including the employment of counsel reasonably satisfactory to the
     Indemnified Party and the payment of all fees and expenses incurred in
     connection with defense thereof; provided, that the failure of any
     Indemnified Party to give such notice shall not relieve the Indemnifying
     Party of its obligations or liabilities pursuant to this Agreement, except
     (and only) to the extent that it shall be finally determined by a court of
     competent jurisdiction (which determination is not subject to appeal or
     further review) that such failure shall have prejudiced the Indemnifying
     Party.

          An Indemnified Party shall have the right to employ separate counsel
     in any such Proceeding and to participate in the defense thereof, but the
     fees and expenses of such counsel shall be at the expense of such
     Indemnified Party or Parties unless: (1) the Indemnifying Party has agreed
     in writing to pay such fees and expenses; (2) the

                                       9

<PAGE>

     Indemnifying Party shall have failed promptly to assume the defense of such
     Proceeding and to employ counsel reasonably satisfactory to such
     Indemnified Party in any such Proceeding; or (3) the named parties to any
     such Proceeding (including any impleaded parties) include both such
     Indemnified Party and the Indemnifying Party, and counsel to the
     Indemnified Party shall reasonably believe that a material conflict of
     interest is likely to exist if the same counsel were to represent such
     Indemnified Party and the Indemnifying Party (in which case, if such
     Indemnified Party notifies the Indemnifying Party in writing that it elects
     to employ separate counsel at the expense of the Indemnifying Party, the
     Indemnifying Party shall not have the right to assume the defense thereof
     and the reasonable fees and expenses of no more than one separate counsel
     shall be at the expense of the Indemnifying Party). The Indemnifying Party
     shall not be liable for any settlement of any such Proceeding effected
     without its written consent, which consent shall not be unreasonably
     withheld or delayed. No Indemnifying Party shall, without the prior written
     consent of the Indemnified Party, effect any settlement of any pending
     Proceeding in respect of which any Indemnified Party is a party, unless
     such settlement includes an unconditional release of such Indemnified Party
     from all liability on claims that are the subject matter of such
     Proceeding.

          Subject to the terms of this Agreement, all reasonable fees and
     expenses of the Indemnified Party (including reasonable fees and expenses
     to the extent incurred in connection with investigating or preparing to
     defend such Proceeding in a manner not inconsistent with this Section)
     shall be paid to the Indemnified Party, as incurred, within ten Trading
     Days of written notice thereof to the Indemnifying Party; provided, that
     the Indemnified Party shall promptly reimburse the Indemnifying Party for
     that portion of such fees and expenses applicable to such actions for which
     such Indemnified Party is judicially determined to be not entitled to
     indemnification hereunder.

          (d) Contribution. If the indemnification under Section 5(a) or 5(b) is
     unavailable to an Indemnified Party or insufficient to hold an Indemnified
     Party harmless for any Losses, then each Indemnifying Party shall
     contribute to the amount paid or payable by such Indemnified Party, in such
     proportion as is appropriate to reflect the relative fault of the
     Indemnifying Party and Indemnified Party in connection with the actions,
     statements or omissions that resulted in such Losses as well as any other
     relevant equitable considerations. The relative fault of such Indemnifying
     Party and Indemnified Party shall be determined by reference to, among
     other things, whether any action in question, including any untrue or
     alleged untrue statement of a material fact or omission or alleged omission
     of a material fact, has been taken or made by, or relates to information
     supplied by, such Indemnifying Party or Indemnified Party, and the parties'
     relative intent, knowledge, access to information and opportunity to
     correct or prevent such action, statement or omission. The amount paid or
     payable by a party as a result of any Losses shall be deemed to include,
     subject to the limitations set forth in this Agreement, any reasonable
     attorneys' or other fees or expenses incurred by such party in connection
     with any Proceeding to the extent such party would have been indemnified
     for such fees or expenses if the indemnification provided for in this
     Section was available to such party in accordance with its terms.

                                       10

<PAGE>

          The parties hereto agree that it would not be just and equitable if
     contribution pursuant to this Section 5(d) were determined by pro rata
     allocation or by any other method of allocation that does not take into
     account the equitable considerations referred to in the immediately
     preceding paragraph. Notwithstanding the provisions of this Section 5(d),
     no Holder shall be required to contribute, in the aggregate, any amount in
     excess of the amount by which the net proceeds actually received by such
     Holder from the sale of the Registrable Securities subject to the
     Proceeding exceeds the amount of any damages that such Holder has otherwise
     been required to pay by reason of such untrue or alleged untrue statement
     or omission or alleged omission, except in the case of fraud by such
     Holder.

          The indemnity and contribution agreements contained in this Section
     are in addition to any liability that the Indemnifying Parties may have to
     the Indemnified Parties.

     6. Miscellaneous

          (a) Remedies. In the event of a breach by the Company or by a Holder,
     of any of their respective obligations under this Agreement, each Holder or
     the Company, as the case may be, in addition to being entitled to exercise
     all rights granted by law and under this Agreement, including recovery of
     damages, will be entitled to specific performance of its rights under this
     Agreement. The Company and each Holder agree that monetary damages would
     not provide adequate compensation for any losses incurred by reason of a
     breach by it of any of the provisions of this Agreement and hereby further
     agrees that, in the event of any action for specific performance in respect
     of such breach, it shall not assert or shall waive the defense that a
     remedy at law would be adequate.

          (b) No Piggyback on Registrations. Except as set forth on Schedule
     6(b) attached hereto, neither the Company nor any of its security holders
     (other than the Holders in such capacity pursuant hereto) may include
     securities of the Company in the initial Registration Statement other than
     the Registrable Securities. The Company shall not file any other
     registration statements until the initial Registration Statement required
     hereunder is declared effective by the Commission, provided that this
     Section 6(b) shall not prohibit the Company from filing amendments to
     registration statements already filed.

          (c) Compliance. Each Holder covenants and agrees that it will comply
     with the prospectus delivery requirements of the Securities Act as
     applicable to it in connection with sales of Registrable Securities
     pursuant to a Registration Statement.

          (d) Discontinued Disposition. Each Holder agrees by its acquisition of
     Registrable Securities that, upon receipt of a notice from the Company of
     the occurrence of any event of the kind described in Section 3(d), such
     Holder will forthwith discontinue disposition of such Registrable
     Securities under a Registration Statement until it is advised in writing
     (the "Advice") by the Company that the use of the applicable Prospectus (as
     it may have been supplemented or amended) may be resumed. The Company will
     use its best efforts to ensure that the use of the Prospectus may be
     resumed

                                       11

<PAGE>

     as promptly as it practicable. The Company agrees and acknowledges that any
     periods during which the Holder is required to discontinue the disposition
     of the Registrable Securities hereunder shall be subject to the provisions
     of Section 2(b).

          (e) Piggy-Back Registrations. If at any time during the Effectiveness
     Period there is not an effective Registration Statement covering all of the
     Registrable Securities and the Company shall determine to prepare and file
     with the Commission a registration statement relating to an offering for
     its own account or the account of others under the Securities Act of any of
     its equity securities, other than on Form S-4 or Form S-8 (each as
     promulgated under the Securities Act) or their then equivalents relating to
     equity securities to be issued solely in connection with any acquisition of
     any entity or business or equity securities issuable in connection with the
     stock option or other employee benefit plans, then the Company shall send
     to each Holder a written notice of such determination and, if within
     fifteen days after the date of such notice, any such Holder shall so
     request in writing, the Company shall include in such registration
     statement all or any part of such Registrable Securities such Holder
     requests to be registered; provided, however, that, the Company shall not
     be required to register any Registrable Securities pursuant to this Section
     6(e) that are eligible for resale pursuant to Rule 144(k) promulgated under
     the Securities Act or that are the subject of a then effective Registration
     Statement.

          (f) Amendments and Waivers. The provisions of this Agreement,
     including the provisions of this sentence, may not be amended, modified or
     supplemented, and waivers or consents to departures from the provisions
     hereof may not be given, unless the same shall be in writing and signed by
     the Company and each Holder of the then outstanding Registrable Securities.
     Notwithstanding the foregoing, a waiver or consent to depart from the
     provisions hereof with respect to a matter that relates exclusively to the
     rights of Holders and that does not directly or indirectly affect the
     rights of other Holders may be given by Holders of all of the Registrable
     Securities to which such waiver or consent relates; provided, however, that
     the provisions of this sentence may not be amended, modified, or
     supplemented except in accordance with the provisions of the immediately
     preceding sentence.

          (g) Notices. Any and all notices or other communications or deliveries
     required or permitted to be provided hereunder shall be delivered as set
     forth in the Purchase Agreement.

          (h) Successors and Assigns. This Agreement shall inure to the benefit
     of and be binding upon the successors and permitted assigns of each of the
     parties and shall inure to the benefit of each Holder. The Company may not
     assign its rights (except by merger) or obligations hereunder without the
     prior written consent of all of the Holders of the then-outstanding
     Registrable Securities. Each Holder may assign their respective rights
     hereunder in the manner and to the Persons as permitted under the Purchase
     Agreement.

          (i) No Inconsistent Agreements. Neither the Company nor any of its
     Subsidiaries has entered, as of the date hereof, nor shall the Company or
     any of its Subsidiaries, on or after the date of this Agreement, enter into
     any agreement with respect

                                       12

<PAGE>

     to its securities, that would have the effect of impairing the rights
     granted to the Holders in this Agreement or otherwise conflicts with the
     provisions hereof. Except as set forth on Schedule 6(i), neither the
     Company nor any of its subsidiaries has previously entered into any
     agreement granting any registration rights with respect to any of its
     securities to any Person that have not been satisfied in full.

          (j) Execution and Counterparts. This Agreement may be executed in two
     or more counterparts, all of which when taken together shall be considered
     one and the same agreement and shall become effective when counterparts
     have been signed by each party and delivered to the other party, it being
     understood that both parties need not sign the same counterpart. In the
     event that any signature is delivered by facsimile transmission or by
     e-mail delivery of a ".pdf" format data file, such signature shall create a
     valid and binding obligation of the party executing (or on whose behalf
     such signature is executed) with the same force and effect as if such
     facsimile or ".pdf" signature page were an original thereof.

          (k) Governing Law. All questions concerning the construction,
     validity, enforcement and interpretation of this Agreement shall be
     determined in accordance with the provisions of the Purchase Agreement.

          (l) Cumulative Remedies. The remedies provided herein are cumulative
     and not exclusive of any other remedies provided by law.

          (m) Severability. If any term, provision, covenant or restriction of
     this Agreement is held by a court of competent jurisdiction to be invalid,
     illegal, void or unenforceable, the remainder of the terms, provisions,
     covenants and restrictions set forth herein shall remain in full force and
     effect and shall in no way be affected, impaired or invalidated, and the
     parties hereto shall use their commercially reasonable efforts to find and
     employ an alternative means to achieve the same or substantially the same
     result as that contemplated by such term, provision, covenant or
     restriction. It is hereby stipulated and declared to be the intention of
     the parties that they would have executed the remaining terms, provisions,
     covenants and restrictions without including any of such that may be
     hereafter declared invalid, illegal, void or unenforceable.

          (n) Headings. The headings in this Agreement are for convenience only,
     do not constitute a part of this Agreement, and shall not be deemed to
     limit or affect any of the provisions hereof.

          (o) Independent Nature of Holders' Obligations and Rights. The
     obligations of each Holder hereunder are several and not joint with the
     obligations of any other Holder hereunder, and no Holder shall be
     responsible in any way for the performance of the obligations of any other
     Holder hereunder. Nothing contained herein or in any other agreement or
     document delivered at any closing, and no action taken by any Holder
     pursuant hereto or thereto, shall be deemed to constitute the Holders as a
     partnership, an association, a joint venture or any other kind of entity,
     or create a presumption that the Holders are in any way acting in concert
     with respect to such obligations or the transactions contemplated by this
     Agreement. Each Holder shall be entitled to protect

                                       13

<PAGE>

     and enforce its rights, including without limitation the rights arising out
     of this Agreement, and it shall not be necessary for any other Holder to be
     joined as an additional party in any proceeding for such purpose.

                            *************************

                                       14

<PAGE>

          IN WITNESS WHEREOF, the parties have executed this Registration Rights
Agreement as of the date first written above.

                                        ALFACELL CORPORATION

                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------

                       [SIGNATURE PAGE OF HOLDERS FOLLOWS]

<PAGE>

                     [SIGNATURE PAGE OF HOLDERS TO ACEL RRA]

Name of Holder: _______________________________________________________
Signature of Authorized Signatory of Holder: __________________________
Name of Authorized Signatory: _________________________________________
Title of Authorized Signatory: ________________________________________

                           [SIGNATURE PAGES CONTINUE]

                                       16

<PAGE>

                                     ANNEX A

                              Plan of Distribution

     Each Selling Stockholder (the "Selling Stockholders") of the common stock
and any of their pledgees, assignees and successors-in-interest may, from time
to time, sell any or all of their shares of common stock on the principal
Trading Market or any other stock exchange, market or trading facility on which
the shares are traded or in private transactions. These sales may be at fixed or
negotiated prices. A Selling Stockholder may use any one or more of the
following methods when selling shares:

          -    ordinary brokerage transactions and transactions in which the
               broker-dealer solicits purchasers;

          -    block trades in which the broker-dealer will attempt to sell the
               shares as agent but may position and resell a portion of the
               block as principal to facilitate the transaction;

          -    purchases by a broker-dealer as principal and resale by the
               broker-dealer for its account;

          -    an exchange distribution in accordance with the rules of the
               applicable exchange;

          -    privately negotiated transactions;

          -    settlement of short sales entered into after the effective date
               of the registration statement of which this prospectus is a part;

          -    broker-dealers may agree with the Selling Stockholders to sell a
               specified number of such shares at a stipulated price per share;

          -    through the writing or settlement of options or other hedging
               transactions, whether through an options exchange or otherwise;

          -    a combination of any such methods of sale; or

          -    any other method permitted pursuant to applicable law.

     The Selling Stockholders may also sell shares under Rule 144 under the
Securities Act of 1933, as amended (the "Securities Act"), if available, rather
than under this prospectus.

     Broker-dealers engaged by the Selling Stockholders may arrange for other
brokers-dealers to participate in sales. Broker-dealers may receive commissions
or discounts from the Selling Stockholders (or, if any broker-dealer acts as
agent for the purchaser of shares, from the purchaser) in amounts to be
negotiated, but, except as set forth in a supplement to this Prospectus, in the
case of an agency transaction not in excess of a customary brokerage commission
in compliance with NASDR Rule 2440; and in the case of a principal transaction a
markup or markdown in compliance with NASDR IM-2440.

                                       17

<PAGE>

     In connection with the sale of the common stock or interests therein, the
Selling Stockholders may enter into hedging transactions with broker-dealers or
other financial institutions, which may in turn engage in short sales of the
Common Stock in the course of hedging the positions they assume. The Selling
Stockholders may also sell shares of the common stock short and deliver these
securities to close out their short positions, or loan or pledge the common
stock to broker-dealers that in turn may sell these securities. The Selling
Stockholders may also enter into option or other transactions with
broker-dealers or other financial institutions or the creation of one or more
derivative securities which require the delivery to such broker-dealer or other
financial institution of shares offered by this prospectus, which shares such
broker-dealer or other financial institution may resell pursuant to this
prospectus (as supplemented or amended to reflect such transaction).

     The Selling Stockholders and any broker-dealers or agents that are involved
in selling the shares may be deemed to be "underwriters" within the meaning of
the Securities Act in connection with such sales. In such event, any commissions
received by such broker-dealers or agents and any profit on the resale of the
shares purchased by them may be deemed to be underwriting commissions or
discounts under the Securities Act. Each Selling Stockholder has informed the
Company that it does not have any written or oral agreement or understanding,
directly or indirectly, with any person to distribute the Common Stock. In no
event shall any broker-dealer receive fees, commissions and markups which, in
the aggregate, would exceed eight percent (8%).

     The Company is required to pay certain fees and expenses incurred by the
Company incident to the registration of the shares. The Company has agreed to
indemnify the Selling Stockholders against certain losses, claims, damages and
liabilities, including liabilities under the Securities Act.

     Because Selling Stockholders may be deemed to be "underwriters" within the
meaning of the Securities Act, they will be subject to the prospectus delivery
requirements of the Securities Act including Rule 172 thereunder. In addition,
any securities covered by this prospectus which qualify for sale pursuant to
Rule 144 under the Securities Act may be sold under Rule 144 rather than under
this prospectus. There is no underwriter or coordinating broker acting in
connection with the proposed sale of the resale shares by the Selling
Stockholders.

     We agreed to keep this prospectus effective until the earlier of (i) the
date on which the shares may be resold by the Selling Stockholders without
registration and without regard to any volume limitations by reason of Rule
144(k) under the Securities Act or any other rule of similar effect or (ii) all
of the shares have been sold pursuant to this prospectus or Rule 144 under the
Securities Act or any other rule of similar effect. The resale shares will be
sold only through registered or licensed brokers or dealers if required under
applicable state securities laws. In addition, in certain states, the resale
shares may not be sold unless they have been registered or qualified for sale in
the applicable state or an exemption from the registration or qualification
requirement is available and is complied with.

     Under applicable rules and regulations under the Exchange Act, any person
engaged in the distribution of the resale shares may not simultaneously engage
in market making activities with respect to the common stock for the applicable
restricted period, as defined in Regulation

                                       18

<PAGE>

     M, prior to the commencement of the distribution. In addition, the Selling
     Stockholders will be subject to applicable provisions of the Exchange Act
     and the rules and regulations thereunder, including Regulation M, which may
     limit the timing of purchases and sales of shares of the common stock by
     the Selling Stockholders or any other person. We will make copies of this
     prospectus available to the Selling Stockholders and have informed them of
     the need to deliver a copy of this prospectus to each purchaser at or prior
     to the time of the sale.

                                       19

<PAGE>

                                                                         ANNEX B

                              ALFACELL CORPORATION

                 SELLING SECURITYHOLDER NOTICE AND QUESTIONNAIRE

     The undersigned beneficial owner of common stock, par value $0.001 per
share (the "Common Stock"), of Alfacell Corporation, a Delaware corporation (the
"Company"), (the "Registrable Securities") understands that the Company has
filed or intends to file with the Securities and Exchange Commission (the
"Commission") a registration statement on Form S-3 (the "Registration
Statement") for the registration and resale under Rule 415 of the Securities Act
of 1933, as amended (the "Securities Act"), of the Registrable Securities, in
accordance with the terms of the Registration Rights Agreement, dated as of July
__, 2006 (the "Registration Rights Agreement"), among the Company and the
Purchasers named therein. A copy of the Registration Rights Agreement is
available from the Company upon request at the address set forth below. All
capitalized terms not otherwise defined herein shall have the meanings ascribed
thereto in the Registration Rights Agreement.

     Certain legal consequences arise from being named as a selling
securityholder in the Registration Statement and the related prospectus.
Accordingly, holders and beneficial owners of Registrable Securities are advised
to consult their own securities law counsel regarding the consequences of being
named or not being named as a selling securityholder in the Registration
Statement and the related prospectus.

                                     NOTICE

     The undersigned beneficial owner (the "Selling Securityholder") of
Registrable Securities hereby elects to include the Registrable Securities owned
by it and listed below in Item 3 (unless otherwise specified under such Item 3)
in the Registration Statement.

                                       20

<PAGE>

The undersigned hereby provides the following information to the Company and
represents and warrants that such information is accurate:

                                  QUESTIONNAIRE

1.   NAME.

     (a)  Full Legal Name of Selling Securityholder

          ______________________________________________________________________

     (b)  Full Legal Name of Registered Holder (if not the same as (a) above)
          through which Registrable Securities Listed in Item 3 below are held:

          ______________________________________________________________________

     (c)  Full Legal Name of Natural Control Person (which means a natural
          person who directly or indirectly alone or with others has power to
          vote or dispose of the securities covered by the questionnaire):

          ______________________________________________________________________

2.   ADDRESS FOR NOTICES TO SELLING SECURITYHOLDER:

________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Telephone: _____________________________________________________________________
Fax: ___________________________________________________________________________
Contact Person: ________________________________________________________________
E-mail Address: ________________________________________________________________

3.   BENEFICIAL OWNERSHIP OF REGISTRABLE SECURITIES:

     (a)  Type and Number of Registrable Securities beneficially owned (not
          including the Registrable Securities that are issuable pursuant to the
          Purchase Agreement):

          _________________________________________________________________
          _________________________________________________________________
          _________________________________________________________________

                                       21

<PAGE>

4.   BROKER-DEALER STATUS:

     (a)  Are you a broker-dealer?

                               Yes       No
                                   -----    -----

     (b)  If "yes" to Section 4(a), did you receive your Registrable Securities
          as compensation for investment banking services to the Company.

                               Yes       No
                                   -----    -----

     Note: If no, the Commission's staff has indicated that you should be
          identified as an underwriter in the Registration Statement.

     (c)  Are you an affiliate of a broker-dealer?

                               Yes       No
                                   -----    -----

     (d)  If you are an affiliate of a broker-dealer, do you certify that you
          bought the Registrable Securities in the ordinary course of business,
          and at the time of the purchase of the Registrable Securities to be
          resold, you had no agreements or understandings, directly or
          indirectly, with any person to distribute the Registrable Securities?

                               Yes       No
                                   -----    -----

     Note: If no, the Commission's staff has indicated that you should be
          identified as an underwriter in the Registration Statement.

5.   BENEFICIAL OWNERSHIP OF OTHER SECURITIES OF THE COMPANY OWNED BY THE
     SELLING SECURITYHOLDER.

     Except as set forth below in this Item 5, the undersigned is not the
     beneficial or registered owner of any securities of the Company other than
     the Registrable Securities listed above in Item 3.

     (a)  Type and Amount of Other Securities beneficially owned by the Selling
          Securityholder:

          _________________________________________________________________
          _________________________________________________________________

                                       22

<PAGE>

6.   RELATIONSHIPS WITH THE COMPANY:

     Except as set forth below, neither the undersigned nor any of its
     affiliates, officers, directors or principal equity holders (owners of 5%
     of more of the equity securities of the undersigned) has held any position
     or office or has had any other material relationship with the Company (or
     its predecessors or affiliates) during the past three years.

     State any exceptions here:

     ______________________________________________________________________
     ______________________________________________________________________

     The undersigned agrees to promptly notify the Company of any inaccuracies
or changes in the information provided herein that may occur subsequent to the
date hereof at any time while the Registration Statement remains effective.

     By signing below, the undersigned consents to the disclosure of the
information contained herein in its answers to Items 1 through 6 and the
inclusion of such information in the Registration Statement and the related
prospectus and any amendments or supplements thereto. The undersigned
understands that such information will be relied upon by the Company in
connection with the preparation or amendment of the Registration Statement and
the related prospectus.

     IN WITNESS WHEREOF the undersigned, by authority duly given, has caused
this Notice and Questionnaire to be executed and delivered either in person or
by its duly authorized agent.

Dated:                                  Beneficial Owner:
       ------------------------------                     ----------------------

                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------

PLEASE FAX OR SEND A PDF COPY OF THE COMPLETED AND EXECUTED NOTICE AND
QUESTIONNAIRE, AND RETURN THE ORIGINAL BY OVERNIGHT MAIL, TO:

Joshua A. Beser
Heller Ehrman LLP
Times Square Tower, 7 Times Square
New York, NY 10036
Phone: (212) 847-8643
Fax: (212) 847-7600
E-mail: joshua.beser@hellerehrman.com

                                       23<PAGE>

                                                                     Exhibit 4.3

                           AGREEMENT TO AMEND WARRANT

     This Agreement is dated as of July 17, 2006, by and between Knoll Capital
Management, L.P. ("Knoll") and Alfacell Corporation (the "Company").

     The undersigned hereby agree as follows:

     1. In connection with the Securities Purchase Agreement (the "Purchase
Agreement") dated as of the date hereof by and among the Company and the
purchasers of securities (the "Purchasers") that are a party thereto (including
affiliates of Knoll), the Company and Knoll have agreed to amend the terms of a
warrant to purchase 592,500 shares of the Company's common stock held by Knoll
Capital Fund II and a warrant to purchase 592,500 shares of the Company's common
stock held by Europa International, Inc. (collectively, the "Original
Warrants").

     2. Each of the Original Warrants shall be amended to reflect the following:

          -    The exercise price per share of Company common stock will be
               reduced to $2.88 per share.

          -    The Warrant will not be exercisable until six months from the
               Closing Date (as defined in the Purchase Agreement).

          Otherwise, the terms of the Original Warrants shall remain the same.

     3. On the Closing Date, The Company will issue new warrants to each of
Knoll Capital Fund II and Europa International, Inc. to reflect the amended
terms (collectively, the "Amended Warrants"). Knoll shall return the Original
Warrants to the Company as soon as practicable and upon receipt, they will be
cancelled and destroyed. In the event Knoll does not return the Original
Warrants to the Company, they shall be deemed cancelled; and, provided further,
that whether or not the Original Warrants are returned, the books and records of
the Company shall be updated to reflect the cancellation of the Original
Warrants and the issuance of the Amended Warrants.

     4. Knoll acknowledges that the terms of the Purchase Agreement and this
Agreement will be disclosed on a Form 8-K to be filed by the Company (the
"8-K"). Knoll consents to the disclosure of such terms, including the
identification of Knoll as a Purchaser in the 8-K.

<PAGE>

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the day and year first above written.

                                        KNOLL CAPITAL MANAGEMENT, L.P.

                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Its:
                                             -----------------------------------

AGREED AND ACCEPTED:

ALFACELL CORPORATION

By: /s/ Kuslima Shogen
    ---------------------------------
Name: Kuslima Shogen
Its: Chief Executive Officer

                                        2

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00107-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00107-of-00352.parquet"}]]