THE SECURITIES REPRESENTED BY THIS WARRANT MAY NOT BE OFFERED FOR SALE, SOLD OR
OTHERWISE TRANSFERRED EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT
FILED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR PURSUANT TO AN EXEMPTION
FROM REGISTRATION UNDER SUCH ACT.

Void after 5:00 P.M., New York Time, on December 31, 2002

                                                           Warrant to Purchase
                                                           __________ Shares of
                                                           Common Stock



                CLASS E REDEEMABLE COMMON STOCK PURCHASE WARRANT


                  This Is to Certify That, FOR VALUE RECEIVED,

                                 ---------------

is entitled to purchase, subject to the provisions of this Warrant, from SELECT
THERAPEUTICS INC. (the "Company"), a Delaware corporation, at any time on or
after February 19, 2001 (the "effective date"), and not later than 5:00 P.M.,
New York time, on December 31, 2002,__________ shares of Common Stock of the
Company at a purchase price per share of $2.00; provided, however, that the
number of shares of Common Stock to be received upon the exercise of this
Warrant and the price to be paid for a share of Common Stock shall be adjusted
form time to time as hereinafter set forth. The shares of Common Stock
deliverable upon such exercise, and as adjusted from time to time, are
hereinafter sometimes referred to as "Warrant Stock" and the exercise price of
this Warrant in effect at any time and as adjusted from time to time is
hereinafter sometimes referred to as the "Exercise Price". The above-named
registered owner of this Warrant and its permitted transferees and/or assignees
are hereinafter referred to as, collectively, the "Holder".

     (a) Exercise of Warrant. This Warrant may be exercised in whole or in part
at any time or from time to time on or after the effective date, but not later
than 5:00 P.M., New York time, on December 31, 2002, or if such expiration date
is a day on which banking institutions are authorized by law to close, then on
the next succeeding day which shall not be such a day, by presentation and
surrender hereof to the Company with the Purchase Form annexed hereto duly
executed and accompanied by payment of the Exercise Price for the number of
shares of Warrant Stock specified in such form, together with all federal and
state taxes applicable upon such exercise. If this Warrant should be exercised
in part only,


<PAGE>

the Company shall, upon surrender of this Warrant for cancellation, execute and
deliver a new warrant evidencing the right of the Holder to purchase the balance
of the Warrant Stock purchasable hereunder. At the close of business on the day
of receipt by the Company of this Warrant at the office or agency of the
Company, in proper form for exercise and accompanied by payment as aforesaid for
the Warrant Stock to be acquired, the Holder shall be deemed to be the holder of
record of the number of fully paid and non_assessable shares of Common Stock
issuable upon such exercise, notwithstanding that the stock transfer books of
the Company shall then be closed or that certificates representing such shares
of Common Stock shall not then actually be delivered to the Holder.

     (b) Reservation of Shares. The Company hereby agrees that at all times
there shall be reserved for issuance and/or delivery upon exercise of this
Warrant such number of shares of its Common Stock as shall be required for
issuance or delivery upon exercise of this Warrant.

     (c) Fractional Shares. No fractional shares or scrip representing
fractional shares shall be issued upon the exercise of this Warrant. With
respect to any fraction of a share called for upon any exercise hereof, the
Company shall pay to the holder an amount in cash equal to such fraction
multiplied by the current market value of such fractional share, determined as
follows:

          (1) If the Common Stock is listed on a national securities exchange or
     admitted to unlisted trading privileges on such exchange, the current value
     shall be the last reported sales price of the Common Stock on such exchange
     on the last trading day prior to the date of exercise of this Warrant, or
     if no such sale is made on such day, the average closing bid and asked
     prices for such day on the composite tape of such exchange; or

          (2) If the Common Stock is not so listed or admitted to unlisted
     trading privileges, the current value shall be the mean of the last
     reported bid and asked prices reported by the National Association of
     Securities Dealers Automated Quotation System ("NASDAQ") (or, if not
     reported by NASDAQ, then reported by the National Quotation Bureau, Inc.)
     on the last trading day prior to the date of the exercise of this Warrant;
     or

          (3) If the Common Stock is not so listed or admitted to unlisted
     trading privileges and bid and asked prices are not so reported, the
     current value shall be an amount, not less than fully diluted book value,
     determined in such reasonable manner as may be prescribed by the Board of
     Directors of the Company, such determination to be final and binding on the
     Holder.


                                        2
<PAGE>

     (d) Exchange, Assignment or Loss of Warrant. This Warrant is exchangeable,
without expense, at the option of the Holder, upon presentation and surrender
hereof to the Company or at the office of its stock transfer agent, if any, for
other Warrants of different denominations entitling the Holder thereof to
purchase in the aggregate the same amount of Warrant Stock purchasable
hereunder. Any such assignment shall be made by surrender of this Warrant to the
Company or at the office of its stock transfer agent, if any, with the
Assignment Form annexed hereto duly executed and funds sufficient to pay any
transfer tax; whereupon the Company shall, without charge, execute and deliver a
new Warrant in the name of the assignee named in such instrument of assignment
and this Warrant shall promptly be cancelled. This Warrant may be divided or
combined with other Warrants which carry the same rights upon presentation
hereof at the office of the Company or at the office of its stock transfer
agent, if any, together with a written notice specifying the names and
denominations in which new Warrants are to be issued. The term "Warrant" as used
herein includes any Warrants issued in substitution for or replacement of this
Warrant, or into which this Warrant may be divided or exchanged. Upon receipt by
the Company of evidence satisfactory to it of the loss, theft, destruction or
mutilation of this Warrant, and (in the case of loss, theft or destruction) of
indemnification reasonably satisfactory in form and substance to its counsel,
and upon surrender and cancellation of this Warrant, if mutilated, the Company
will execute and deliver a new Warrant of like tenor and date. Any such new
Warrant executed and delivered shall constitute an additional contractual
obligation on the part of the Company, whether or not this Warrant so lost,
stolen, destroyed, or mutilated, shall be at any time enforceable by anyone.

     (e) Rights of the Holder. The Holder shall not, by virtue hereof, be
entitled to any rights of a shareholder of the Company, either at law or in
equity, and the rights of the Holder are limited to those expressed in this
Warrant and are not enforceable against the Company except to the extent set
forth herein.

     (f) Anti-Dilution Provisions.

          (1) Stock Dividends, Subdivisions and Combinations. If the Company
     shall at any time issue Common Stock by way of dividend or other
     distribution on the Common Stock of the Company, or subdivide or combine
     the outstanding shares of Common Stock, then the Exercise Price shall be
     proportionately decreased in the case of such issuance (on the day
     following the date fixed for determining shareholders entitled to receive
     such dividend


                                        3
<PAGE>

     or other distribution) or decreased in the case of such subdivision or
     increased in the case of such combination (on the date that such
     subdivision or combination shall become effective). Upon any adjustment of
     the Exercise Price pursuant to this Section (f)(1), the holder of this
     Warrant shall thereafter (until another such adjustment) be entitled to
     purchase, at the new Exercise Price, the amount of Warrant Stock,
     calculated to the nearest full share, obtained by multiplying the number of
     shares of Warrant Stock then issuable upon exercise of this Warrant by the
     Exercise Price then in effect and dividing the product so obtained by the
     new Exercise Price.

          (2) No Adjustment for Small Amounts. Anything in this Section (f) to
     the contrary notwithstanding, the Company shall not be required to give
     effect to any adjustment in the Exercise Price unless and until the net
     effect of one or more adjustments, determined as above provided, shall have
     required a change of the Exercise Price by at least five percent in such
     Price, but when the cumulative net effect of more than one adjustment so
     determined shall be to change the actual Exercise Price by at least five
     percent, such change in the Exercise Price shall thereupon be given effect.

          (3) Common Stock Defined. Whenever reference is made in this Section
     (f) to the issue or sale of shares of Common Stock, the term "Common Stock"
     shall mean the Common Stock of the Company of the class authorized as of
     the date hereof and any other class of stock ranking on a parity with such
     Common Stock. However, subject to the provisions of Section (i) hereof,
     shares issuable upon exercise hereof shall include only shares of the class
     designated as Common Stock of the Company as of the date hereof.

     (g) Officer's Certificate. Whenever the Exercise Price shall be adjusted as
required by the provisions of Section (f) hereof, the Company shall forthwith
file in the custody of its Secretary or an Assistant Secretary at its principal
office, and with its stock transfer agent, if any, an officer's certificate
showing the adjusted Exercise Price determined as herein provided and setting
forth in reasonable detail the facts requiring such adjustments. Each officer's
certificate shall be made available at all reasonable times for inspection by
the Holder, and the Company shall, forthwith after each such adjustment, mail a
copy of such certificate to the Holder. Such certificate shall be conclusive as
to the correctness of such adjustment.

     (h)  Notices  to  Warrant  Holders.  So  long  as  this  Warrant  shall  be
outstanding and  unexercised,  (i) if the Company shall pay


                                        4
<PAGE>

any dividend or make any distribution upon the Common Stock to the holders
thereof as a group in proportion to their respective shareholdings, or (ii) if
the Company shall offer to the holders of Common Stock, as a group in proportion
to their respective shareholdings, for subscription or purchase by them any
shares of stock of any class or any other rights, or (iii) if any capital
reorganization of the Company, reclassification of the capital stock of the
Company, consolidation or merger of the Company with or into another corporation
(other than a merger in which the Company is the continuing corporation and
which does not result in any reclassification, capital reorganization or other
similar change of outstanding shares of Common Stock of the class issuable upon
exercise of this Warrant), sale, lease or transfer of all or substantially all
of the property and assets of the Company to another corporation, or voluntary
or involuntary dissolution, liquidation or winding up of the Company shall be
effected, then, in any such case, the Company shall cause to be delivered to the
Holder, at least ten days prior to the date specified in (x) or (y) below, as
the case may be, a notice containing a brief description of the proposed action
and stating the date on which (x) a record is to be taken for the purpose of
such dividend, distribution or rights, or (y) such reclassification,
reorganization, consolida- tion, merger, conveyance, lease, dissolution,
liquidation or winding up is to take place and the date, if any, as of which the
holders of Common Stock of record shall be entitled to exchange their shares of
Common Stock for securities or other property deliverable upon such
reclassification, reorganization, consolidation, merger, conveyance,
dissolution, liquidation or winding up.

     (i) Reclassification, Reorganization or Merger. In case of any
reclassification, capital reorganization or other change of outstanding shares
of Common Stock of the Company (other than a change in par value or to par
value, or as a result of an issuance of Common Stock by way of dividend or other
distribution or of a subdivision or combination), or in case of any
consolidation or merger of the Company with or into another corporation (other
than a merger in which the Company is the continuing corporation and which does
not result in any reclassification, capital reorganization or other similar


                                        5
<PAGE>

change of outstanding shares of Common Stock of the class issuable upon exercise
of this Warrant), or in case of any sale or conveyance to any other corporation
of the property and assets of the Company as an entirety or substantially as an
entirety, the Company shall cause effective provision to be made so that the
Holder shall have the right thereafter, by exercising this Warrant, to purchase
the kind and amount of shares of securities and other property receivable upon
such reclassification, capital reorganization or other similar change,
consolidation, merger, sale or conveyance as if the Holder had exercised this
Warrant prior to such transaction. Any such provision shall include provision
for adjustments which shall be as nearly equivalent as may be practicable to the
adjustments provided for in this Warrant. The foregoing provisions of this
Section (i) shall similarly apply to successive reclassifications, capital
reorganizations and similar changes of shares of Common Stock and to successive
consolidations, mergers, sales or conveyances.

     (j) Spin-Offs. In the event the Company spins_off a subsidiary by
distributing to the shareholders of the Company, as a dividend or otherwise, the
stock of the subsidiary, the Company shall reserve, for the life of the Warrant,
shares of the subsidiary to be delivered to the Holder upon exercise of the
Warrant to the same extent as if Holder was the owner of record of the Warrant
Stock on the record date for payment of the shares of the subsidiary.

     (k) "Piggyback" Registration Rights.

          (1)  Definitions.  As used in this Section (k),  the  following  terms
     shall have the following meanings:

               (a) The term "Holder" shall mean any person owning or having the
          right to acquire Registrable Securities or any permitted transferee of
          a Holder.

               (b) The terms "register", "registered" and "registration" refer
          to a registration effected by preparing and filing a registration
          statement or similar document (except a Registration Statement filed
          for a purpose which would render inappropriate the covenants of the
          Company contained in this Section (k) such as a Registration Statement
          on Form S-8 or any other inappropriate form), in compliance with the
          Securities Act of 1933, as amended (the "Securities Act"), and the
          declaration or order of effectiveness of such registration statement
          or document.

               (c) The term "Registrable Securities" shall mean the Warrant
          Stock; provided, however, that securities shall only be treated as
          Registrable Securities if and only for so long as they (A) have not
          been disposed of pursuant to a registration statement declared
          effective by the Securities and Exchange Commission ("SEC"), (B) have
          not been sold in a transaction exempt from the registration and
          prospectus delivery requirements of the Securities Act wherein all
          transfer restrictions and restrictive legends with respect thereto are
          removed upon the consummation of such sale and (C) are held by a
          Holder or a permitted transferee of a Holder pursuant to Section
          (k)(10) below.


                                        6
<PAGE>

          (2) Registration under the Securities Act.

               (a) In the event that at any time before the second anniversary
          of the effective date of this Warrant the Company intends to register
          securities which relate to a current offering of securities of the
          Company, the Company shall give written notice (the "Company Notice")
          of such intention to the Holder, and upon receipt within 30 days after
          the giving of the Company Notice of the written request of the Holder,
          the Company shall include in such registration the Registrable
          Securities of the Holder so as to permit the public sale thereof by
          the Holder in compliance with the Securities Act. Neither the delivery
          of a Company Notice nor of a registration request by any Holder shall
          in any way obligate the Company to file such Registration Statement.
          Notwithstanding the filing of the Registration Statement the Company
          may, at any time prior to the effective date thereof, determine not to
          offer the securities to which it relates, without liability to the
          Holder except that the Company shall pay such expenses as are to be
          paid by it under Section (k)(5).

               (b) In no event shall the Company be obligated to file more than
          one registration statement for the subject Registrable Securities on
          account of the registration rights granted to the Holders thereof.

          (3) Obligations of the Company. Whenever required under this Section
     (k) to include Registrable Securities in a registration statement, the
     Company shall, as expeditiously as reasonably possible:

               (a) Use its reasonable best efforts to cause such registration
          statement to become effective, and, upon the request of the Holders of
          a majority of the Registrable Securities registered thereunder, keep
          such registration statement effective for a period of up to 120 days
          or until the distribution contemplated in the Registration Statement
          has been completed and, during the period that such registration
          statement is required to be maintained hereunder, file such
          post-effective amendments and supplements thereto as may be required
          by the Securities Act and the rules and regulations thereunder or
          otherwise to ensure that the prospectus included therein does not
          contain any untrue statement of material fact or omit to state a fact
          required to be stated therein or necessary to make the statements
          contained therein, in light of the circumstances under which they are
          made, not misleading; provided, however, that such 120-day period
          shall be extended for a period of time equal to the period that the
          Holder refrains from selling any securities included in such
          registration at the request of an underwriter of Common Stock (or
          other


                                        7
<PAGE>

          securities) of the Company, and provided further that if applicable
          rules under the Securities Act governing the obligation to file a
          post-effective amendment permit, in lieu of filing a post-effective
          amendment that (i) includes any prospectus required by Section
          10(a)(3) of the Securities Act or (ii) reflects facts or events
          representing a material or fundamental change in the information set
          forth in the registration statement, the Company may incorporate by
          reference information required to be included in (i) and (ii) above to
          the extent such information is contained in periodic reports filed
          pursuant to Section 13 or 15(d) of the Securities Exchange Act of
          1934, as amended (the "Exchange Act"), in the registration statement.

               (b) Prepare and file with the SEC such amendments and supplements
          to such registration statement, and the prospectus used in connection
          with such registration statement, as may be necessary to comply with
          the provisions of the Securities Act with respect to the disposition
          of all securities covered by such registration statement.

               (c) Furnish to the Holders such numbers of copies of a
          prospectus, including a preliminary prospectus as amended or
          supplemented from time to time, in conformity with the requirements of
          the Securities Act, and such other documents as they may reasonably
          request in order to facilitate the disposition of Registrable
          Securities owned by them.

               (d) Use its reasonable best efforts to register and qualify the
          Registrable Securities covered by such registration statement under
          such other federal or state securities laws of such jurisdictions as
          shall be reasonably requested by the Holders; provided, however, that
          the Company shall not be required in connection therewith or as a
          condition thereto to qualify to do business or to file a general
          consent to service of process in any such states or jurisdictions,
          unless the Company is already subject to service in such jurisdiction
          and except as may be required by the Securities Act.

               (e) In the event of any underwritten public offering, enter into
          and perform its obligations under an underwriting agreement, in usual
          and customary form, with the managing underwriter of such offering.
          Each Holder participating in such underwriting shall also enter into
          and perform its obligations under such an agreement.

               (f) At any time when a prospectus relating to Registrable
          Securities covered by such registration statement is required to be
          delivered under the Securities Act, notify each


                                        8
<PAGE>

          Holder (i) when the registration statement or any post-effective
          amendment and supplement thereto has become effective, (ii) of the
          issuance by the SEC of any stop order or the initiation of proceedings
          for that purpose (in which event the Company shall make every effort
          to obtain the withdrawal of any order suspending effectiveness of the
          registration statement at the earliest possible time or prevent the
          entry thereof), (iii) of the receipt by the Company of any
          notification with respect to the suspension of the qualification of
          the Registrable Securities for sale in any jurisdiction or the
          initiation of any proceeding for such purpose and (iv) of the
          happening of any event as a result of which the prospectus included in
          such registration statement, as then in effect, includes an untrue
          statement of a material fact or omits to state a material fact
          required to be stated therein or necessary to make the statements
          therein not misleading in the light of the circumstances then
          existing.

               (g) Cause all such Registrable Securities registered hereunder to
          be listed on each securities exchange or quotation service on which
          similar securities issued by the Company are then listed or quoted.

               (h) Provide a transfer agent and registrar for all Registrable
          Securities registered hereunder and a CUSIP number for all such
          Registrable Securities, in each case not later than the effective date
          of such registration.

          (4) Holders' Obligation to Furnish Information. It shall be a
     condition precedent to the obligation of the Company to take any action
     pursuant to this Section (k) with respect to the Registrable Securities of
     any selling Holder that such Holder shall furnish to the Company such
     information regarding the Holder, the Registrable Securities held by the
     Holder, and the intended method of disposition of such securities as shall
     be reasonably required by the Company to effect the registration of such
     Holder's Registrable Securities.

          (5) Expenses of Piggyback Registration . The Company shall bear and
     pay all expenses incurred in connection with any registration of
     Registrable Securities pursuant to Section (k)(2)(a) for each Holder,
     including (without limitation) all registration, filing, and qualification
     fees, printers and accounting fees relating or apportionable thereto, but
     excluding underwriting discounts and commissions relating to Registrable
     Securities; provided, however, that the Company shall not bear the cost of
     any professional fees or costs of accounting, financial or legal advisors
     to any of the Holders. Notwithstanding the


                                        9
<PAGE>

     foregoing, each Holder shall pay all registration expenses that such Holder
     is required to pay under applicable law.

          (6) Underwriting Requirements. In connection with any offering
     involving an underwriting of shares of the Company's capital stock, the
     Company shall not be required under Section (k)(2) to include any of the
     Holders' Registrable Securities in such underwriting unless they accept the
     terms of the underwriting as agreed upon between the Company and the
     underwriters selected by it (or by other persons entitled to select the
     underwriters), and then only in such quantity as the underwriters determine
     in their sole discretion will not jeopardize the success of the offering by
     the Company. If the total amount of securities, including Registrable
     Securities, requested by selling stockholder to be included in such
     offering exceeds the amount of securities to be sold other than by the
     Company that the underwriters determine in their sole discretion is
     compatible with the success of the offering, then the Company shall be
     required to include in the offering only that number of such securities,
     including Registrable Securities, which the underwriters determine in their
     sole discretion will not jeopardize the success of the offering (the
     securities so included to be apportioned pro rata among the selling
     stockholders, including the Holders, according to the total amount of
     securities entitled to be included therein owned by each selling
     stockholder or in such other proportions as shall mutually be agreed to by
     such selling stockholders). For purposes of the preceding parenthetical
     concerning apportionment, for any selling stockholder who is a Holder of
     Registrable Securities and is a partnership or corporation, the partners,
     retired partners and stockholders of such holder, or the estates and family
     members of any such partners and retired partners and any trusts for the
     benefit of any of the foregoing persons shall be deemed to be a single
     "selling stockholder", and any pro-rata reduction with respect to such
     "selling stockholder" shall be based upon the aggregate amount of shares
     carrying registration rights owned by all entities and individuals included
     in such "selling stockholder", as defined in this sentence.

          (7) Delay of Registration. No Holder shall have any right to obtain or
     seek an injunction restraining or otherwise delaying any such registration
     as the result of any controversy that might arise with respect to the
     interpretation or implementation of these Registration Rights.

          (8) Indemnification. In the event that any Registrable Securities are
     included in a registration statement under this Section (k)(2):


                                       10
<PAGE>

               (a) To the extent permitted by law, the Company will indemnify
          and hold harmless each Holder, any underwriter (as defined in the
          Securities Act) for such Holder and each person, if any, who controls
          such Holder or underwriter within the meaning of the Securities Act or
          the Exchange Act, against any losses, claims, damages, or liabilities
          (joint or several) to which they may become subject under the
          Securities Act, or the Exchange Act, insofar as such losses, claims,
          damages, or liabilities (or actions in respect thereof) arise out of
          or are based upon any of the following statements, omissions or
          violations (collectively a "Violation"): (i) any untrue statement or
          alleged untrue statement of a material fact contained in such
          registration statement, including any preliminary prospectus or final
          prospectus contained therein or any amendments or supplements thereto,
          (ii) the omission or alleged omission to state therein a material fact
          required to be stated therein, or necessary to make the statements
          therein not misleading, or (iii) any violation or alleged violation by
          the Company of the Securities Act, the Exchange Act, or any rule or
          regulation promulgated under the Securities Act, or the Exchange Act,
          and the Company will pay to each such Holder, underwriter or
          controlling person, as incurred, any legal or other expenses
          reasonably incurred by them in connection with investigating or
          defending any such loss, claim, damage, liability, or action;
          provided, however, that the indemnity agreement contained in this
          Section (k)(8) shall not apply to amounts paid in settlement of any
          such loss, claim, damage, liability, or action if such settlement is
          effected without the consent of the Company (which consent shall not
          be unreasonably withheld), nor shall the Company be liable in any such
          case for any such loss, claim, damage, liability, or action to the
          extent that it arises out of or is based upon a Violation which occurs
          in reliance upon and in conformity with written information furnished
          expressly for use in connection with such registration by any such
          Holder, underwriter or controlling person.

               (b) To the extent permitted by law, each selling Holder will
          indemnify and hold harmless the Company, each of its directors, each
          of its officers who has signed the registration statement, each
          person, if any, who controls the Company within the meaning of the
          Securities Act, any underwriter, any other person selling securities
          in such registration statement and any controlling person of any such
          underwriter or other person, against any losses, claims, damages, or
          liabilities (joint or several) to which any of the foregoing persons
          may become subject, under the Securities Act, or the Exchange Act,
          insofar as such losses, claims, damages, or liabilities (or actions in
          respect thereto) arise out of or are based upon any Violation, in each
          case to the extent (and only to the extent) that such Violation occurs


                                       11
<PAGE>

          in reliance upon and in conformity with written information furnished
          by such Holder expressly for use in connection with such registration;
          and each such Holder will pay, as incurred, any legal or other
          expenses reasonably incurred by any person intended to be indemnified
          pursuant to this Section (8)(b), in connection with investigating or
          defending any such loss, claim, damage, liability, or action;
          provided, however, that the indemnity agreement contained in this
          Section (8)(b) shall not apply to amounts paid in settlement of any
          such loss, claim, damage, liability or action if such settlement is
          effected without the consent of the Holder, which consent shall not be
          unreasonably withheld; provided, that, in no event shall any indemnity
          under this Section (8)(b) exceed the gross proceeds from the offering
          received by such Holder.

               (c) Promptly after receipt by an indemnified party under this
          Section (8) of notice of the commencement of any action (including any
          governmental action), such indemnified party shall, if a claim in
          respect thereof is to be made against any indemnifying party under
          this Section (8), deliver to the indemnifying party a written notice
          of the commencement thereof and the indemnifying party shall have the
          right to participate in, and, to the extent the indemnifying party so
          desires, jointly with any other indemnifying party similarly notified,
          to assume the defense thereof with counsel selected by the
          indemnifying party and approved by the indemnified party (whose
          approval shall not be unreasonably withheld); provided, however, that
          an indemnified party (together with all other indemnified parties
          which may be represented without conflict by one counsel) shall have
          the right to retain one separate counsel, with the fees and expenses
          to be paid by the indemnifying party, if representation of such
          indemnified party by the counsel retained by the indemnifying party
          would be inappropriate due to actual or potential differing interests
          between such indemnified party and any other party represented by such
          counsel in such proceeding. The failure to deliver written notice to
          the indemnifying party within a reasonable time of the commencement of
          any such action, if prejudicial to its ability to defend such action,
          shall relieve such indemnifying party of any liability to the
          indemnified party under this Section (8), but the omission so to
          deliver written notice to the indemnifying party will not relieve it
          of any liability that it may have to any indemnified party otherwise
          than under this Section (8).

               (d) If the indemnification provided for in this Section (8) is
          held by a court of competent jurisdiction to be unavailable to an
          indemnified party with respect to any loss, liability, claim, damage,
          or expense referred to therein, then the indemnifying party, in lieu
          of indemnifying such indemnified party


                                       12
<PAGE>

          hereunder, shall contribute to the amount paid or payable by such
          indemnified party as a result of such loss, liability, claim, damage,
          or expense in such proportion as is appropriate to reflect the
          relative fault of the indemnifying party on the one hand and of the
          indemnified party on the other in connection with the statements or
          omissions that resulted in such loss, liability, claim, damage, or
          expense as well as any other relevant equitable considerations. The
          relative fault of the indemnifying party and of the indemnified party
          shall be determined by reference to, among other things, whether the
          untrue or alleged untrue statement of a material fact or the omission
          to state a material fact relates to information supplied by the
          indemnifying party or by the indemnified party and the parties'
          relative intent, knowledge, access to information, and opportunity to
          correct or prevent such statement or omission.

               (e) Notwithstanding the foregoing, to the extent that the
          provisions on indemnification and contribution contained in the
          underwriting agreement entered into in connection with the
          underwritten public offering are in conflict with the foregoing
          provisions, the provisions in the underwriting agreement shall
          control.

               (f) The obligations of the Company and Holders under this Section
          (8) shall survive the completion of any offering of Registrable
          Securities in a registration statement under these Registration
          Rights, and otherwise.

          (9) Reports under the Exchange Act. With a view to making available to
     the Holders the benefits of Rule 144 and any other rule or regulation of
     the SEC that may at any time permit a Holder to sell securities of the
     Company to the public pursuant to an exemption from registration, the
     Company agrees to:

               (a) File with the SEC in a timely manner all reports and other
          documents required of the Company under the Securities Act and the
          Exchange Act; and

               (b) Furnish to any Holder, so long as the Holder owns any
          Registrable Securities, forthwith upon request (i) a copy of the most
          recent annual or quarterly report of the Company and such other
          reports and documents so filed by the Company, and (ii) such other
          information as may be reasonably requested in availing any Holder of
          any rule or regulation of the SEC which permits the selling of any
          such securities without registration or pursuant to such form.

          (10) Permitted Transferees. The right to cause the Company to register
     Registrable  Securities  granted  to the Holder by


                                       13
<PAGE>

     the Company under this Warrant may be assigned in full by a Holder in
     connection with a transfer by such Holder of its Registrable Securities if:
     (a) such Holder gives prior written notice to the Company; (b) such
     transferee agrees to comply with the terms and provisions of this
     Agreement; (c) such transfer is otherwise in compliance with this Agreement
     and (d) such transfer is otherwise be effected in accordance with
     applicable securities laws. Except as specifically permitted by this
     Section (10), the rights of a Holder with respect to Registrable Securities
     as set out herein shall not be transferable to any other person, and any
     attempted transfer shall cause all rights of such Holder therein to be
     forfeited.

          (11) Termination of Registration Rights. The right of any Holder to
     request the filing or inclusion in any registration pursuant to Section
     (k)(2) shall terminate if all Registrable Securities held by such Holder
     may immediately be sold under Rule 144.

     (l) Redemption of Warrants. Provided the closing price of the Company's
Common Stock is $4.00 or more for 10 consecutive trading days, the Company shall
have the right to call the Warrants for redemption at a price of $.001 per
Warrant at any time. The Company shall give no less than 10 days written notice
of redemption to the Holders as of the date of such notice. Such notice shall
set a date not more than 90 days after the date of the redemption notice (the
"Redemption Date"). Upon the Redemption Date, the Warrants shall be cancelled
and shall thereafter be null and void and of no effect, and the Company shall
pay to the Holders as of the date of the notice the above redemption price upon
surrender of their Warrants. No Warrant will be subject to redemption unless at
the time of the giving of such notice the Company has an effective registration
statement under the Securities Act registering its sale of the Warrant Stock.

     (m) Transfer to Comply with the Securities Act.

          (1) This Warrant, or any new warrant issued pursuant to Section (d)
     hereof, or the Warrant Stock or any other security issued or issuable upon
     exercise of this Warrant, may not be offered or sold except in conformity
     with the Securities Act and then only against receipt of an agreement of
     such person to whom such offer of sale is made to comply with the
     provisions of this Section (m) with respect to any resale or other
     disposition of such securities.


                                       14
<PAGE>

          (2) The Company may cause a customary legend for securities not
     registered under the Securities Act to be set forth on each certificate
     representing Warrant Stock or any other security issued or issuable upon
     exercise of this Warrant not theretofore distributed to the public or sold
     to underwriters for distribution to the public pursuant to Section (k)
     hereof, unless counsel for the Company is of the opinion as to any such
     certificate that such legend is unnecessary.

     (n) Notices. All notices, requests, claims, demands and other
communications hereunder shall be in writing and shall be given either (i) by
delivery in person, in which case any such notice shall be deemed to have been
duly given upon receipt, or (ii) by certified mail, (postage paid and return
receipt requested),in which case said notice will be deemed to have been duly
given three (3) days after such mailing, to the respective parties as follows:

           If to the Company:

                     Select Therapeutics Inc.
                     50 Cummings Park
                     Woburn, MA 01801
                     Attn:  Robert Bender, Chairman

           If to Holder:

                     ------------


or to such other address as either party may have furnished to the other in
writing in accordance herewith, except that notices of a change of address shall
only be effective upon receipt.

     (o)  Governing  Law.  This  Warrant  shall be governed by and  construed in
accordance  with  the laws of the  State  of New  York,  without  regard  to the
principles of conflict of laws.

     (p) No Prior Agreements. This Warrant (i) contains the entire agreement,
and supersedes all other prior agreements and understandings, both written and
oral, between the parties hereto with respect to the subject matter hereof, and
(ii) is not intended to confer upon any other person any rights or remedies
hereunder.


                                       15
<PAGE>

     (q) Effect of Headings. The section headings herein are for convenience
only and shall not affect the meaning or construction of this Agreement.

                                      SELECT THERAPEUTICS INC.


                                       By: ____________________________
                                           Robert Bender, Chairman


                CLASS E REDEEMABLE COMMON STOCK PURCHASE WARRANT


                                       16
<PAGE>

                                                                  PURCHASE FORM


                                           Dated ______________, 20___

     The undersigned hereby irrevocably elects to exercise the within Warrant to
the extent of purchasing _____________ shares of Common Stock of SELECT
THERAPEUTICS INC. and hereby makes payment of $__________ in payment of the
actual exercise price thereof.

                     INSTRUCTIONS FOR REGISTRATION OF STOCK

Name
     ---------------------------------------------------------------------------
     (please typewrite or print in block letters)

Address
        ------------------------------------------------------------------------

Signature
          ----------------------------------------------------------------------

Social Security or Employer I.D. No.
                                     -------------------------------------------


                                 ASSIGNMENT FORM


     FOR VALUE RECEIVED,
                        --------------------------------------------------------

hereby sells, assigns and transfers unto

Name
     ---------------------------------------------------------------------------
         (please typewrite or print in block letters)

Address
        ------------------------------------------------------------------------

the right to purchase Common Stock, represented by this Warrant to the extent of
________________________ shares as to which right is exercisable, and does
hereby irrevocably constitute and appoint _______________________, attorney, to
transfer the same on the books of the Company with full power of substitution in
the premises.


                                   Signature ____________________________


Dated: _______________________, 20___


                                       17