EXHIBIT 4.1



NEITHER THIS SECURITY
NOR THE SECURITIES INTO WHICH THIS SECURITY IS CONVERTIBLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR
THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED
(THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD OR OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED
EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR PURSUANT TO AN AVAILABLE EXEMPTION FROM, OR
IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE WITH APPLICABLE STATE SECURITIES
LAWS AS EVIDENCED BY A LEGAL OPINION OF COUNSEL TO THE TRANSFEROR TO SUCH EFFECT, THE SUBSTANCE OF WHICH SHALL BE REASONABLY ACCEPTABLE
TO THE COMPANY.



Original Issue Date: __________, 2012



$_______________





5% ORIGINAL ISSUE DISCOUNT UNSECURED
CONVERTIBLE DEBENTURE

DUE __________, 2013



THIS 5% ORIGINAL ISSUE
DISCOUNT UNSECURED CONVERTIBLE DEBENTURE is one of a series of duly authorized and validly issued 5% Original Issue Discount Unsecured
Convertible Debentures of SpectraScience, Inc., a Minnesota corporation, (the “Company”), having its principal
place of business at 11568 Sorrento Valley Rd., Suite 11, San Diego, California 92121, designated as its 5% Original Issue Discount
Unsecured Convertible Debenture due _______________, 2013 (this debenture, the “Debenture” and, collectively
with the other debentures of such series, the “Debentures”).



FOR VALUE RECEIVED,
the Company promises to pay to ________________________ or its registered assigns (the “Holder”), or shall have
paid pursuant to the terms hereunder, the principal sum of $_______________ on __________, 2013 (the “Maturity Date”)
or such earlier date as this Debenture is required or permitted to be repaid as provided hereunder, and to pay interest to the
Holder on the aggregate unconverted and then outstanding principal amount of this Debenture in accordance with the provisions hereof.
This Debenture is subject to the following additional provisions:



Section
1.	Definitions. For the purposes hereof, in addition to the terms defined elsewhere in this Debenture, (a) capitalized
terms not otherwise defined herein shall have the meanings set forth in the Purchase Agreement and (b) the following terms shall
have the following meanings:





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"Affiliate”
means any Person that, directly or indirectly through one or more intermediaries, controls or is controlled by or is under common
control with a Person, as such terms are used in and construed under Rule 405 under the Securities Act.



“Alternate
Consideration” shall have the meaning set forth in Section 5(b).



“Bankruptcy
Event” means any of the following events: (a) the Company or any Significant Subsidiary (as such term is defined in Rule
1-02(w) of Regulation S-X) thereof commences a case or other proceeding under any bankruptcy, reorganization, arrangement, adjustment
of debt, relief of debtors, dissolution, insolvency or liquidation or similar law of any jurisdiction relating to the Company or
any Significant Subsidiary thereof, (b) there is commenced against the Company or any Significant Subsidiary thereof any such case
or proceeding that is not dismissed within 60 days after commencement, (c) the Company or any Significant Subsidiary thereof is
adjudicated insolvent or bankrupt or any order of relief or other order approving any such case or proceeding is entered, (d) the
Company or any Significant Subsidiary thereof suffers any appointment of any custodian or the like for it or any substantial part
of its property that is not discharged or stayed within 60 calendar days after such appointment, (e) the Company or any Significant
Subsidiary thereof makes a general assignment for the benefit of creditors, (f) the Company or any Significant Subsidiary thereof
calls a meeting of its creditors with a view to arranging a composition, adjustment or restructuring of its debts or (g) the Company
or any Significant Subsidiary thereof, by any act or failure to act, expressly indicates its consent to, approval of or acquiescence
in any of the foregoing or takes any corporate or other action for the purpose of effecting any of the foregoing.



“Beneficial
Ownership Limitation” shall have the meaning set forth in Section 4(c).



“Business
Day” means any day except any Saturday, any Sunday, any day which shall be a federal legal holiday in the United States
or any day on which banking institutions in the State of New York are authorized or required by law or other governmental action
to close.



“Buy-In”
shall have the meaning set forth in Section 4(d)(iv).



“Change
of Control Transaction” means the occurrence after the date hereof of any of either (a) an acquisition after the date
hereof by an individual or legal entity or “group” (as described in Rule 13d-5(b)(1) promulgated under the Exchange
Act) of effective control (whether through legal or beneficial ownership of capital stock of the Company, by contract or otherwise)
of in excess of 60% of the voting securities of the Company (other than by means of conversion or exercise of the Debentures and
the Securities issued together with the Debentures), (b) the Company merges into or consolidates with any other Person, or any
Person merges into or consolidates with the Company and, after giving effect to such transaction, the shareholders of the Company
immediately prior to such transaction own less than 50% of the aggregate voting power of the Company or the successor entity of
such transaction, or (c) the Company sells or transfers all or substantially all of its assets to another Person and the shareholders
of the Company immediately prior to such transaction own less than 50% of the aggregate voting power of the acquiring entity immediately
after the transaction, and a replacement at one time or within a three year period of more than one-half of the members of the
Board of Directors which is not approved by a majority of those individuals who are members of the Board of Directors on the date
hereof (or by those individuals who are serving as members of the Board of Directors on any date whose nomination to the Board
of Directors was approved by a majority of the members of the Board of Directors who are members on the date hereof), or (e) the
execution by the Company of an agreement to which the Company is a party or by which it is bound, providing for any of the events
set forth in clauses (a) through (d) above.





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“Common
Stock Equivalents” means any securities of the Company or the Subsidiaries which would entitle the holder thereof to
acquire at any time Common Stock, including, without limitation, any debt, preferred stock, rights, options warrants, or other
instrument that is at any time convertible into or exercisable or exchangeable for, or otherwise entitles the holder thereof to
receive Common Stock.



“Conversion”
shall have the meaning ascribed to such term in Section 4.



“Conversion
Date” shall have the meaning set forth in Section 4(a).



“Conversion
Price” shall have the meaning set forth in Section 4(b).



“Conversion
Schedule” means the Conversion Schedule in the form of Schedule 1 attached hereto.



“Conversion
Shares” means, collectively, the shares of Common Stock issuable upon conversion of this Debenture in accordance with
the terms hereof.



“Debenture
Register” shall have the meaning set forth in Section 2(c).



“Event
of Default” shall have the meaning set forth in Section 8(a).



“Equity
Conditions” means, during the period in question, (a) the Company shall have duly honored
all conversions by virtue of one or more Notices of Conversion of the Holder, if any, (b) the Company shall have paid all liquidated
damages and other amounts owing to the Holder in respect of this Debenture,(c) the Common Stock is trading on a Trading
Market and all of the shares issuable pursuant to the Transaction Documents are listed or quoted for trading on such Trading Market
(and the Company believes, in good faith, that trading of the Common Stock on a Trading Market will continue uninterrupted for
the foreseeable future), (d) there is a sufficient number of authorized but unissued and otherwise unreserved shares of Common
Stock for the issuance of all of the shares issuable pursuant to the Transaction Documents, (e) there is no existing Event of Default
or no existing event which, with the passage of time or the giving of notice, would constitute an Event of Default, (f) the issuance
of the shares in question to the Holder would not violate the limitations set forth in Section 4(c) herein provided that
any shares proposed to be issued that would cause a violation of Section 4(c) will be automatically deemed canceled by the Company
and upon such cancellation this clause (f) shall be satisfied, (g) there has been no public announcement
of a pending or proposed Fundamental Transaction or Change of Control Transaction that has not been consummated, and (h) the Holder
is not in possession of any information provided by the Company that constitutes, or may constitute, material non-public information
other than information required to be provided by the Company under the Subscription Agreement.





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“Exchange
Act” means the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder.



“Exempt
Issuance” means the issuance of (a) shares of Common Stock or options to employees, officers, consultants, advisors or
directors of the Company pursuant to any stock or option plan duly adopted for such purpose by a majority of the existing members
of the Board of Directors or a majority of the members of a committee of directors established for such purpose, (b) securities
upon the exercise or exchange of or conversion of any Securities issued hereunder and/or other securities exercisable or exchangeable
for or convertible into shares of Common Stock issued and outstanding on the date of this Agreement, provided that such securities
have not been amended since the date of this Agreement to increase the number of such securities or to decrease the exercise, exchange
or conversion price of such securities, (c) securities issued pursuant to acquisitions or strategic transactions approved by a
majority of the disinterested directors of the Company, provided that any such issuance shall only be to a Person which is, itself
or through its subsidiaries, an operating company in a business synergistic with the business of the Company and in which the Company
receives benefits in addition to the investment of funds, but shall not include a transaction in which the Company is issuing securities
primarily for the purpose of raising capital or to an entity whose primary business is investing in securities, and (d) issuances
of restricted securities issued by the Company from time to time for the payment of services or to vendors, which shares are not
issued for cash consideration in an amount not to exceed 750,000 shares per calendar year.



“Fundamental
Transaction” shall have the meaning set forth in Section 5(b).



“Interest
Notice Period” shall have the meaning set forth in Section 2(a).



“Interest
Payment Date” shall have the meaning set forth in Section 2(a).



“Interest
Share Amount” shall have the meaning set forth in Section 2(a).



"Interest
Rate" shall mean sixteen percent (16%) per annum.



“Late
Fees” shall have the meaning set forth in Section 2(d).





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“Liens”
means a lien, charge, security interest, encumbrance, right of first refusal, preemptive right or other restriction.



“Mandatory
Default Amount” means the sum of (a) 100% of the outstanding principal amount of this Debenture, plus 100% of accrued
and unpaid interest hereon, and (b) all other amounts, costs, expenses and liquidated damages due in respect of this Debenture.



“New
York Courts” shall have the meaning set forth in Section 9(d).



“Notice
of Conversion” shall have the meaning set forth in Section 4(a).



“Original
Issue Date” means the date of the first issuance of the Debentures, regardless of any transfers of any Debenture and
regardless of the number of instruments which may be issued to evidence such Debentures.



“Permitted
Indebtedness” means (a) the indebtedness evidenced by the Debentures and any prior issued Debentures (b) lease obligations
and purchase money indebtedness of up to $500,000, in the aggregate, incurred in connection with the acquisition of capital assets
and lease obligations with respect to newly acquired or leased assets,(c) trade account payables
and expenses incurred in the ordinary course of business, (d) wages and other compensation due to employees and agents for services
performed, (e) liabilities for taxes not yet due, (f) liabilities for customer deposits, (g) indebtedness existing on the date
hereof, and (h) indebtedness of the Company to any Subsidiary and of any Subsidiary to the Company or any other Subsidiary.



“Permitted
Lien” means the individual and collective reference to the following: (a) Liens for taxes, assessments and other governmental
charges or levies not yet due or Liens for taxes, assessments and other governmental charges or levies being contested in good
faith and by appropriate proceedings for which adequate reserves (in the good faith judgment of the management of the Company)
have been established in accordance with GAAP; (b) deposits or pledges to secure bids, tenders, contracts, leases, statutory obligations,
performance bonds, surety and appeal bonds and other obligations of like nature arising in the ordinary course of the Company’s
business; (c) deposits or pledges to secure obligations under workers’ compensation, social security or similar laws, or
under unemployment insurance or general liability or product liability insurance; (d) Liens imposed by law which were incurred
in the ordinary course of the Company’s business, such as carriers’, warehousemen’s and mechanics’ Liens,
statutory landlords’ Liens, and other similar Liens arising in the ordinary course of the Company’s business, and which
(x) do not individually or in the aggregate materially detract from the value of such property or assets or materially impair the
use thereof in the operation of the business of the Company and its consolidated Subsidiaries or (y) are being contested in good
faith by appropriate proceedings, which proceedings have the effect of preventing for the foreseeable future the forfeiture or
sale of the property or asset subject to such Lien; and (e) Liens incurred in connection with Permitted Indebtedness under clause
(a) thereunder; and (f) Liens incurred in connection with Permitted Indebtedness under clause (b) thereunder, provided that such
Liens are not secured by assets of the Company or its Subsidiaries other than the assets so acquired or leased; (g) Liens existing
on the date hereof; (h) any attachment or judgment Lien not constituting an Event of Default; and (i) easements, rights of way,
restrictions, and other similar charges or encumbrances not interfering in any material respect with the ordinary conduct of the
business of the Company.





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“Person”
means an individual or corporation, partnership, trust, incorporated or unincorporated association, joint venture, limited liability
company, joint stock company, government (or an agency or subdivision thereof) or other entity of any kind.



“Purchase
Agreement” means the Subscription Agreement, dated as of __________, 2012 among the Company and the original Holders,
as amended, modified or supplemented from time to time in accordance with its terms.



“Securities
Act” means the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder.



“Share
Delivery Date” shall have the meaning set forth in Section 4(d)(ii).



“Subsidiary”
shall have the meaning set forth in the Purchase Agreement.



“Trading
Day” means a day on which the New York Stock Exchange is open for business.



“Trading
Market” means the following markets or exchanges on which the Common Stock is listed or quoted for trading on the date
in question: the NYSE AMEX LLC, the Nasdaq Capital Market, the Nasdaq Global Market, the Nasdaq Global Select Market, the New York
Stock Exchange, the OTC Bulletin Board or the other OTC markets, including the OTCQX, OTCQB and OTC Pink Markets.



“Transaction
Documents” shall have the meaning set forth in the Purchase Agreement.



Section 2.	Interest.



a)	Payment
of Interest in Cash or Kind. The Company shall pay interest to the Holder at the Interest Rate on the aggregate principal amount
of the principal being converted on any Conversion Date (as to that principal amount then being converted), and on the Maturity
Date (each such date, an “Interest Payment Date”) (if any Interest Payment Date is not a Business Day, then
the applicable payment shall be due on the next succeeding Business Day), in cash or, at the Company’s option, in duly authorized,
validly issued, fully paid and non-assessable shares of Common Stock (the dollar amount to be paid in shares, the “Interest
Share Amount”) or a combination thereof; provided, however, that payment in shares of Common Stock on account
of interest may only occur if (i) all of the Equity Conditions have been met (unless waived by the Holder in writing) during the
2 Trading Days immediately prior to the applicable Interest Payment Date (the “Interest Notice Period”) and
through and including the date such shares of Common Stock are actually issued to the Holder, (ii) the Notice of Conversion delivered
by the Holder to Company affirms that the issuance of the Conversion Shares on account of principal and interest will not violate
Section 4(c) hereunder. To the extent that any such issuance of Conversion Shares on account of interest under this Section 2(a)
would violate section 4(c), such interest shall either be paid in cash or at the Company's election deferred and paid in Conversion
Shares at the next Conversion Date.





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b)	Company’s
Election to Pay Interest in Cash or Shares of Common Stock. Subject to the terms and conditions herein, the decision whether
to pay interest hereunder in cash, shares of Common Stock or a combination thereof shall be at the sole discretion of the Company.



c)	Interest
Calculations. Interest on the principal balance of this Note shall be calculated on the basis of a 360-day year, consisting
of twelve 30 calendar day periods, and shall accrue daily commencing on the Original Issue Date until payment in full of the outstanding
principal, together with all accrued and unpaid interest, liquidated damages and other amounts which may become due hereunder,
has been made. Interest shall cease to accrue with respect to any principal amount converted, provided that, the Company actually
delivers the Conversion Shares within the time period required by Section 4(d)(ii) herein. Interest hereunder will be paid to the
Person in whose name this Debenture is registered on the records of the Company regarding registration and transfers of this Debenture
(the “Debenture Register”). Except as otherwise provided herein, if at any time the Company pays interest partially
in cash and partially in shares of Common Stock to the holders of the Debentures, then such payment of cash shall be distributed
ratably among the holders of the then-outstanding Debentures based on their (or their predecessor’s) initial purchases of
Debentures pursuant to the Purchase Agreement.



d)Late
Fee. All overdue accrued and unpaid interest to be paid hereunder shall entail a late fee at an interest rate equal to the
lesser of 18% per annum or the maximum rate permitted by applicable law (the “Late Fees”) which shall accrue
daily from the date such interest is due hereunder through and including the date of actual payment in full.



e)	Prepayment.
Except as otherwise set forth in this Debenture, the Company may not prepay any portion of the principal amount of this Debenture
without the prior written consent of the Holder.



Section 3.	
Registration of Transfers and Exchanges.



a)	Different
Denominations. This Debenture is exchangeable for an equal aggregate principal amount of Debentures of different authorized
denominations, as requested by the Holder surrendering the same. No service charge will be payable for such registration of transfer
or exchange.





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b)	Investment
Representations. This Debenture has been issued subject to certain investment representations of the original Holder set forth
in the Purchase Agreement and may be transferred or exchanged only in compliance with the Purchase Agreement and applicable federal
and state securities laws and regulations.



c)	Reliance
on Debenture Register. Prior to due presentment for transfer to the Company of this Debenture, the Company and any agent of
the Company may treat the Person in whose name this Debenture is duly registered on the Debenture Register as the owner hereof
for the purpose of receiving payment as herein provided and for all other purposes, whether or not this Debenture is overdue, and
neither the Company nor any such agent shall be affected by notice to the contrary.



Section 4.	
Conversion.



a)	Voluntary
Conversion. At any time after the Original Issue Date until this Debenture is no longer outstanding, this Debenture shall be
convertible, in whole or in part, into shares of Common Stock at the option of the Holder, at any time and from time to time (subject
to the conversion limitations set forth in Section 4(c) hereof). The Holder shall effect conversions by delivering to the
Company a Notice of Conversion, the form of which is attached hereto as Annex A (each, a “Notice of Conversion”),
specifying therein the principal amount of this Debenture to be converted and the date on which such conversion shall be effected
(such date, the “Conversion Date”). If no Conversion Date is specified in a Notice of Conversion, the Conversion
Date shall be the date that such Notice of Conversion is actually delivered hereunder. To effect conversions hereunder, the Holder
shall not be required to physically surrender this Debenture to the Company unless the entire principal amount of this Debenture,
plus all accrued and unpaid interest thereon, has been so converted. Conversions hereunder shall have the effect of lowering the
outstanding principal amount of this Debenture in an amount equal to the applicable conversion. The Holder and the Company shall
maintain records showing the principal amount(s) converted and the date of such conversion(s). The Company may deliver an objection
to any Notice of Conversion within 1 Business Day of delivery of such Notice of Conversion. In the event of any dispute or discrepancy,
the records of the Company shall be controlling and determinative in the absence of manifest error.



b)	Conversion
Price. The conversion price in effect on any Conversion Date shall be equal to $0.099,subject to adjustment herein
(the “Conversion Price”).



c)	Conversion
Limitations. Holder shall not have the right to convert any portion of this Debenture, pursuant to Section 4 or otherwise,
to the extent that after giving effect to such issuance after conversion the Holder (together with the Holder’s Affiliates,
and any other person or entity acting as a group together with the Holder or any of the Holder’s Affiliates), would beneficially
own in excess of the Beneficial Ownership Limitation (as defined below). For purposes of this Section beneficial ownership shall
be calculated in accordance with Section 13(d) of the Exchange Act and the rules and regulations promulgated thereunder. Holder
is solely responsible for any schedules required to be filed in accordance therewith. The Company shall have no obligation to verify
or confirm the accuracy of such filings.  In any case, the number of outstanding shares of Common Stock shall be determined
after giving effect to the conversion or exercise of securities of the Company, including this Debenture, by the Holder or its
Affiliates since the date as of which such number of outstanding shares of Common Stock was reported. The “Beneficial
Ownership Limitation” shall be 4.99% of the number of shares of the Common Stock outstanding immediately after giving
effect to the issuance of shares of Common Stock issuable upon exercise of this Debenture. The Holder, upon not less than 61 days’
prior notice to the Company, may increase or decrease the Beneficial Ownership Limitation provisions of this Section 4(c), provided
that the Beneficial Ownership Limitation in no event exceeds 9.99% of the number of shares of the Common Stock outstanding immediately
after giving effect to the issuance of shares of Common Stock upon exercise of this Debenture held by the Holder and the provisions
of this Section 4(c) shall continue to apply. Any such increase or decrease will not be effective until the 61st day
after such notice is delivered to the Company. The limitations contained in this paragraph shall apply to a successor holder of
this Debenture.





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d)
Mechanics of Conversion.



i.	Conversion
Shares Issuable Upon Conversion of Principal and Interest Amount. The number of Conversion Shares issuable upon a conversion
hereunder shall be determined by the quotient obtained by dividing (x) the outstanding principal amount and accrued but unpaid
interest of this Debenture to be converted by (y) the Conversion Price.

i.



ii.	Delivery
of Certificate Upon Conversion. Not later than four Trading Days after each Conversion Date (the “Share Delivery Date”),
the Company shall deliver, or cause to be delivered, to the Holder (A) a certificate or certificates representing the Conversion
Shares which, on or after the six month anniversary of the Original Issue Date, shall be free of restrictive legends and trading
restrictions (other than those which may then be required by the Purchase Agreement or applicable law) representing the number
of Conversion Shares being acquired upon the conversion of this Debenture and (B) a bank check in the amount of accrued and unpaid
interest (if the Company has elected or is required to pay accrued interest in cash). On the six month anniversary of the Original
Issue Date, the Company shall use its commercially reasonable efforts to deliver any certificate or certificates required to be
delivered by the Company under this Section 4(d) electronically through the Depository Trust Company or another established clearing
corporation performing similar functions.





iii.	Partial
Liquidated Damages. If the Company is obligated to and fails for any reason to deliver to the Holder such certificate or certificates
pursuant to Section 4(d)(ii) by the fifth Trading Day after the Conversion Date, the Company shall pay to the Holder, in cash,
as liquidated damages and not as a penalty, for each $1,000 of principal amount being converted, $10 per Trading Day (increasing
to $20 per Trading Day on the seventh (7th) Trading Day after such liquidated damages begin to accrue) for each Trading
Day after such fourth (4th) Trading Day until such certificates are delivered. Nothing herein shall limit a Holder’s
right to pursue actual damages or declare an Event of Default pursuant to Section 8 hereof for the Company’s failure to deliver
Conversion Shares within the period specified herein and the Holder shall have the right to pursue all remedies available to it
hereunder, at law or in equity including, without limitation, a decree of specific performance and/or injunctive relief. The exercise
of any such rights shall not prohibit the Holder from seeking to enforce damages pursuant to any other Section hereof or under
applicable law.





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iv.	Compensation
for Buy-In on Failure to Timely Deliver Certificates Upon Conversion. In addition to any other rights available to the Holder,
if the Company is obligated to and fails for any reason to deliver to the Holder such certificate or certificates by the Share
Delivery Date pursuant to Section 4(d)(ii), and if after such Share Delivery Date the Holder is required by its brokerage firm
to purchase (in an open market transaction or otherwise), or the Holder’s brokerage firm otherwise purchases, shares of Common
Stock to deliver in satisfaction of a sale by the Holder of the Conversion Shares which the Holder was entitled to receive upon
the conversion relating to such Share Delivery Date (a “Buy-In”), then the Company shall (A) pay in cash to
the Holder (in addition to any other remedies available to or elected by the Holder) the amount by which (x) the Holder’s
total purchase price (including any brokerage commissions) for the Common Stock so purchased exceeds (y) the product of (1) the
aggregate number of shares of Common Stock that the Holder was entitled to receive from the conversion at issue multiplied by (2)
the actual sale price at which the sell order giving rise to such purchase obligation was executed (including any brokerage commissions)
and (B) at the option of the Holder, either reissue (if surrendered) this Debenture in a principal amount equal to the principal
amount of the attempted conversion or deliver to the Holder the number of shares of Common Stock that would have been issued if
the Company had timely complied with its delivery requirements under Section 4(d)(ii). For example, if the Holder purchases Common
Stock having a total purchase price of $11,000 to cover a Buy-In with respect to an attempted conversion of this Debenture with
respect to which the actual sale price of the Conversion Shares (including any brokerage commissions) giving rise to such purchase
obligation was a total of $10,000 under clause (A) of the immediately preceding sentence, the Company shall be required to pay
the Holder $1,000. The Holder shall provide the Company written notice indicating the amounts payable to the Holder in respect
of the Buy-In and, upon request of the Company, evidence of the amount of such loss. Nothing herein shall limit a Holder’s
right to pursue any other remedies available to it hereunder, at law or in equity including, without limitation, a decree of specific
performance and/or injunctive relief with respect to the Company’s failure to timely deliver certificates representing shares
of Common Stock upon conversion of this Debenture as required pursuant to the terms hereof.





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v.	Reservation
of Shares Issuable Upon Conversion. The Company covenants that it will at all times reserve and keep available out of its authorized
and unissued shares of Common Stock for the sole purpose of issuance upon conversion of this Debenture and payment of interest
on this Debenture, each as herein provided, free from preemptive rights or any other actual contingent purchase rights of Persons
other than the Holder (and the other holders of the Debentures), not less than such aggregate number of shares of the Common Stock
as shall (subject to the terms and conditions set forth in the Purchase Agreement) be issuable (taking into account the adjustments
and restrictions of Section 5) upon the conversion of the outstanding principal amount of this Debenture and payment of interest
hereunder. The Company covenants that all shares of Common Stock that shall be so issuable shall, upon issue, be duly authorized,
validly issued, fully paid and nonassessable.



vi.	Fractional
Shares. No fractional shares or scrip representing fractional shares shall be issued upon the conversion of this Debenture.
As to any fraction of a share which Holder would otherwise be entitled to purchase upon such conversion, the Company shall at its
election, either pay a cash adjustment in respect of such final fraction in an amount equal to such fraction multiplied by the
Conversion Price or round up to the next whole share.



vii.	Transfer
Taxes. The issuance of certificates for Conversion Shares on conversion of this Debenture shall be made without charge to the
Holder hereof for any documentary stamp or similar taxes that may be payable in respect of the issue or delivery of such certificates,
provided that, the Company shall not be required to pay any tax that may be payable in respect of any transfer involved in the
issuance and delivery of any such certificate upon conversion in a name other than that of the Holder of this Debenture so converted
and the Company shall not be required to issue or deliver such certificates unless or until the person or persons requesting the
issuance thereof shall have paid to the Company the amount of such tax or shall have established to the satisfaction of the Company
that such tax has been paid.



Section 5.	Certain
Adjustments.



a)	Stock
Dividends and Stock Splits. If the Company, at any time while this Debenture is outstanding: (i) pays a stock dividend or otherwise
makes a distribution or distributions payable in shares of Common Stock on shares of Common Stock or any Common Stock Equivalents
(which, for avoidance of doubt, shall not include any shares of Common Stock issued by the Company upon conversion of, or payment
of interest on, the Debentures), (ii) subdivides outstanding shares of Common Stock into a larger number of shares, (iii) combines
(including by way of a reverse stock split) outstanding shares of Common Stock into a smaller number of shares or (iv) issues,
in the event of a reclassification of shares of the Common Stock, any shares of capital stock of the Company, then the Conversion
Price shall be multiplied by a fraction of which the numerator shall be the number of shares of Common Stock (excluding any treasury
shares of the Company) outstanding immediately before such event and of which the denominator shall be the number of shares of
Common Stock outstanding immediately after such event. Any adjustment made pursuant to this Section shall become effective immediately
after the record date for the determination of shareholders entitled to receive such dividend or distribution and shall become
effective immediately after the effective date in the case of a subdivision, combination or re-classification.





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b)	Fundamental
Transaction. If, at any time while this Debenture is outstanding, (i) the Company effects any merger or consolidation of the
Company with or into another Person, (ii) the Company effects any sale of all or substantially all of its assets in one transaction
or a series of related transactions, (iii) any tender offer or exchange offer (whether by the Company or another Person) is completed
pursuant to which holders of Common Stock are permitted to tender or exchange their shares for other securities, cash or property,
or (iv) the Company effects any reclassification of the Common Stock or any compulsory share exchange pursuant to which, with respect
to any of the foregoing, the Common Stock is effectively converted into or exchanged for other securities, cash or property (in
any such case, a “Fundamental Transaction”), then, upon any subsequent conversion of this Debenture, the Holder
shall have the right to receive, for each Conversion Share that would have been issuable upon such conversion immediately prior
to the occurrence of such Fundamental Transaction, the same kind and amount of securities, cash or property as it would have been
entitled to receive upon the occurrence of such Fundamental Transaction if it had been, immediately prior to such Fundamental Transaction,
the holder of 1 share of Common Stock (the “Alternate Consideration”). For purposes of any such conversion,
the determination of the Conversion Price shall be appropriately adjusted to apply to such Alternate Consideration based on the
amount of Alternate Consideration issuable in respect of 1 share of Common Stock in such Fundamental Transaction, and the Company
shall apportion the Conversion Price among the Alternate Consideration in a reasonable manner reflecting the relative value of
any different components of the Alternate Consideration. If holders of Common Stock are given any choice as to the securities,
cash or property to be received in a Fundamental Transaction, then the Holder shall be given the same choice as to the Alternate
Consideration it receives upon any conversion of this Debenture following such Fundamental Transaction. To the extent necessary
to effectuate the foregoing provisions, any successor to the Company or surviving entity in such Fundamental Transaction shall
issue to the Holder a new debenture consistent with the foregoing provisions and evidencing the Holder’s right to convert
such debenture into Alternate Consideration. The terms of any agreement pursuant to which a Fundamental Transaction is effected
shall include terms requiring any such successor or surviving entity to comply with the provisions of this Section 5(b) and insuring
that this Debenture (or any such replacement security) will be similarly adjusted upon any subsequent transaction analogous to
a Fundamental Transaction.





12









c)	Calculations.
All calculations under this Section 5 shall be made to the nearest cent or the nearest 1/100th of a share, as the case may be.
For purposes of this Section 5, the number of shares of Common Stock deemed to be issued and outstanding as of a given date shall
be the sum of the number of shares of Common Stock (excluding any treasury shares of the Company) issued and outstanding.



d)	Notice
to the Holder.



i.	Adjustment
to Conversion Price. Whenever the Conversion Price is adjusted pursuant to any provision of this Section 5, the Company shall
promptly deliver to each Holder a notice setting forth the Conversion Price after such adjustment and setting forth a brief statement
of the facts requiring such adjustment.



ii.	Notice
to Allow Conversion by Holder. If (A) the Company shall declare a dividend (or any other distribution in whatever form) on
the Common Stock, (B) the Company shall declare a special nonrecurring cash dividend on or a redemption of the Common Stock, (C)
the Company shall authorize the granting to all holders of the Common Stock of rights or warrants to subscribe for or purchase
any shares of capital stock of any class or of any rights, (D) the approval of any shareholders of the Company shall be required
in connection with any reclassification of the Common Stock, any consolidation or merger to which the Company is a party, any sale
or transfer of all or substantially all of the assets of the Company, of any compulsory share exchange whereby the Common Stock
is converted into other securities, cash or property or (E) the Company shall authorize the voluntary
or involuntary dissolution, liquidation or winding up of the affairs of the Company, then, in each case, the Company shall cause
to be filed at each office or agency maintained for the purpose of conversion of this Debenture, and shall cause to be delivered
to the Holder at its last address as it shall appear upon the Debenture Register, at least twenty (20) calendar days prior to the
applicable record or effective date hereinafter specified, a notice stating(x) the date on which a record is to be taken
for the purpose of such dividend, distribution, redemption, rights or warrants, or if a record is not to be taken, the date as
of which the holders of the Common Stock of record to be entitled to such dividend, distributions, redemption, rights or warrants
are to be determined or (y) the date on which such reclassification, consolidation, merger, sale, transfer or share exchange is
expected to become effective or close, and the date as of which it is expected that holders of the Common Stock of record shall
be entitled to exchange their shares of the Common Stock for securities, cash or other property deliverable upon such reclassification,
consolidation, merger, sale, transfer or share exchange, provided that the failure to deliver such notice or any defect therein
or in the delivery thereof shall not affect the validity of the corporate action required to be specified in such notice. The Holder
is entitled to convert this Debenture during the 20-day period commencing on the date of such notice through the effective date
of the event triggering such notice.





13









Section 6.	Intentionally
Omitted.



Section 7.	Negative
Covenants. As long as any portion of this Debenture remains outstanding, unless the holders of at least 51% in principal amount
of the then outstanding Debentures shall have otherwise given prior written consent, the Company shall not, and shall not permit
any of its subsidiaries (whether or not a Subsidiary on the Original Issue Date) to, directly or indirectly:



a)	other
than Permitted Indebtedness, enter into, create, incur, assume, guarantee or suffer to exist any indebtedness for borrowed money
of any kind, including, but not limited to, a guarantee, on or with respect to any of its property or assets now owned or hereafter
acquired or any interest therein or any income or profits therefrom;



b)	other
than Permitted Liens, enter into, create, incur, assume or suffer to exist any Liens of any kind, on or with respect to any of
its property or assets now owned or hereafter acquired or any interest therein or any income or profits therefrom;



c)	amend
its charter documents, including, without limitation, its amended and restated articles of incorporation, as amended and restated
bylaws, in any manner that materially and adversely affects any rights of the Holder;



d)	repay,
repurchase or offer to repay, repurchase or otherwise acquire more than a de minimis number of shares of its Common
Stock or Common Stock Equivalents other than as to (i) the Conversion Shares or Warrant Shares as permitted or required under the
Transaction Documents and (ii) repurchases of Common Stock or Common Stock Equivalents of departing officers and directors of the
Company, provided that such repurchases shall not exceed an aggregate of $100,000 for all officers and directors during the term
of this Debenture;



e)	repay,
repurchase or offer to repay, repurchase or otherwise acquire any Indebtedness, other than the Debentures or prior issued Debentures
if on a pro-rata basis, and other than regularly scheduled principal and interest payments as such terms are in effect as of the
Original Issue Date, provided that such payments shall not be permitted if, at such time, or after giving effect to such payment,
any Event of Default exists and is continuing or occurs and is continuing;



f)	pay
cash dividends or distributions on any equity securities of the Company;



g)	enter
into any transaction with any Affiliate of the Company which would be required to be disclosed in any public filing with the Commission,
unless such transaction is made on an arm’s-length basis and expressly approved by a majority of the disinterested directors
of the Company (even if less than a quorum otherwise required for board approval); or





14









h)	enter
into any agreement with respect to any of the foregoing.



Section 8.	Events
of Default.



a)	“Event
of Default” means, wherever used herein, any of the following events (whatever the reason for such event and whether
such event shall be voluntary or involuntary or effected by operation of law or pursuant to any judgment, decree or order of any
court, or any order, rule or regulation of any administrative or governmental body):



i.	any default
in the payment of (A) the principal amount of this Debenture or (B) interest, liquidated damages and other amounts owing to a Holder
on any Debenture, as and when the same shall become due and payable (whether on a Conversion Date or the Maturity Date or by acceleration
or otherwise) which default, solely in the case of an interest payment or other default under clause (B) above, is not cured within
5 Trading Days;



ii.the
Company shall fail to observe or perform any other covenant or agreement contained in the Debentures (other than a breach by the
Company of its obligations to deliver shares of Common Stock to the Holder upon conversion, which breach is addressed in clause
(xi) below) which failure is not cured, if possible to cure, within the earlier to occur of (A) 10 Trading
Days after notice of such failure sent by the Holder or by any other Holder to the Company and (B) 15 Trading Days after the Company
has become or should have become aware of such failure;



iii.a
material default or Event of Default (subject to any grace or cure period provided in the applicable agreement, document or instrument)
shall occur under (A) any of the Transaction Documents or (B) any other material agreement, lease, document or instrument to which
the Company or any Subsidiary is obligated (and not covered by clause (vi) below) the result of which would reasonably be expected
to have a material adverse effect on the operating results and financial condition of the Company;



iv.	any
representation or warranty made in this Debenture, any other Transaction Documents, any written statement pursuant hereto or thereto
or any other report, financial statement or certificate made or delivered to the Holder or any other Holder shall be untrue or
incorrect in any material respect as of the date when made or deemed made;





15









v.	the Company
or any Significant Subsidiary (as such term is defined in Rule 1-02(w) of Regulation S-X) shall be subject to a Bankruptcy Event;



vi.	the
Company or any Subsidiary shall default on any of its obligations under any mortgage, credit agreement or other facility, indenture
agreement, factoring agreement or other instrument under which there may be issued, or by which there may be secured or evidenced,
any indebtedness for borrowed money or money due under any long term leasing or factoring arrangement that (a) involves an obligation
greater than $150,000, whether such indebtedness now exists or shall hereafter be created, and (b) results in such indebtedness
becoming or being declared due and payable prior to the date on which it would otherwise become due and payable;



vii.	the
Common Stock shall not be eligible for listing or quotation for trading on a Trading Market and shall not be eligible to resume
listing or quotation for trading thereon within seven Trading Days;



viii.	the
Company shall be a party to any Change of Control Transaction or Fundamental Transaction or shall agree to sell or dispose of all
or in excess of 40% of its assets in one transaction or a series of related transactions (whether or not such sale would constitute
a Change of Control Transaction);



ix.	the
Company shall fail for any reason to deliver certificates to a Holder prior to the fifteenth Trading Day after a Conversion Date
pursuant to Section 4(d) or the Company shall provide at any time notice to the Holder, including by way of public announcement,
of the Company’s intention to not honor requests for conversions of any Debentures in accordance with the terms hereof; or



x.	any monetary
judgment, writ or similar final process shall be entered or filed against the Company, any subsidiary or any of their respective
property or other assets for more than $100,000, and such judgment, writ or similar final process shall remain unvacated, unbonded
or unstayed for a period of 45 calendar days.



b)	Remedies
Upon Event of Default. If any Event of Default occurs, the outstanding principal amount of this Debenture, plus accrued but
unpaid interest, liquidated damages and other amounts owing in respect thereof through the date of acceleration, shall become,
at the election of Holders of twenty-five percent (25%) of the outstanding aggregate principal amount of Debentures, immediately
due and payable in cash at the Mandatory Default Amount, except in the case of an Event of Default pursuant to Section 8(a)(i)(A),
which amounts shall become immediately due and payable in cash at the Mandatory Default Amount at the election of the Holder. Commencing
5 days after the occurrence of and during the continuance of any Event of Default that results in the eventual acceleration of
this Debenture, the interest rate on this Debenture shall accrue at an interest rate equal to the lesser of 18% per annum or the
maximum rate permitted under applicable law. Upon the payment in full of the Mandatory Default Amount, the Holder shall promptly
surrender this Debenture to or as directed by the Company. In connection with such acceleration described herein, the Holder need
not provide, and the Company hereby waives, any presentment, demand, protest or other notice of any kind, and the Holder may immediately
and without expiration of any grace period enforce any and all of its rights and remedies hereunder and all other remedies available
to it under applicable law. Such acceleration may be rescinded and annulled by the election of Holders of twenty-five percent (25%)
of the outstanding aggregate principal amount of Debentures (or by the election of the Holder in the case of an Event of Default
pursuant to Section 8(a)(i)(A)) at any time prior to payment hereunder and the Holder shall have all rights as a holder of the
Debenture until such time, if any, as the Holder receives full payment pursuant to this Section 8(b). No such rescission or annulment
shall affect any subsequent Event of Default or impair any right consequent thereon.





16









Section 9.	Miscellaneous.



a)	Notices.
Any and all notices or other communications or deliveries to be provided by the Holder hereunder, including, without limitation,
any Notice of Conversion, shall be in writing and delivered personally, by facsimile, by electronic communication or sent by a
nationally recognized overnight courier service, addressed to the Company, at the address set forth above, or such other facsimile
number or address as the Company may specify for such purpose by notice to the Holder delivered in accordance with this Section
9(a). Any and all notices or other communications or deliveries to be provided by the Company hereunder shall be in writing and
delivered personally, by facsimile, by electronic communication or sent by a nationally recognized overnight courier service addressed
to each Holder at the facsimile number or address of the Holder appearing on the books of the Company, or if no such facsimile
number or address appears, at the principal place of business of the Holder. Any notice or other communication or deliveries hereunder
shall be deemed given and effective on the earliest of (i) the date of transmission, if such notice or communication is delivered
via facsimile or electronic communication prior to 5:30 p.m. (New York City time), (ii) the date immediately following the date
of transmission, if such notice or communication is delivered via facsimile or electronic communication between 5:30 p.m. (New
York City time) and 11:59 p.m. (New York City time) on any date, (iii) the second Business Day following the date of mailing, if
sent by nationally recognized overnight courier service or (iv) upon actual receipt by the party to whom such notice is required
to be given.



b)	Absolute
Obligation. Except as expressly provided herein, no provision of this Debenture shall alter or impair the obligation of the
Company, which is absolute and unconditional, to pay the principal of, liquidated damages and accrued interest, as applicable,
on this Debenture at the time, place, and rate, and in the coin or currency, herein prescribed. This Debenture is a direct debt
obligation of the Company. This Debenture ranks pari passu with all other Debentures now or hereafter issued under
the terms set forth herein.





17









c)	Lost
or Mutilated Debenture. If this Debenture shall be mutilated, lost, stolen or destroyed, the Company shall execute and deliver,
in exchange and substitution for and upon cancellation of a mutilated Debenture, or in lieu of or in substitution for a lost, stolen
or destroyed Debenture, a new Debenture for the principal amount of this Debenture so mutilated, lost, stolen or destroyed, but
only upon receipt of evidence of such loss, theft or destruction of such Debenture, and of the ownership hereof, reasonably satisfactory
to the Company.



d)	Governing
Law. All questions concerning the construction, validity, enforcement and interpretation of this Debenture shall be governed
by and construed and enforced in accordance with the internal laws of the State of New York, without regard to the principles of
conflict of laws thereof. Each party agrees that all legal proceedings concerning the interpretation, enforcement and defense of
the transactions contemplated by any of the Transaction Documents (whether brought against a party hereto or its respective Affiliates,
directors, officers, shareholders, employees or agents) shall be commenced in the state and federal courts sitting in the City
of New York, Borough of Manhattan (the “New York Courts”). Each party hereto hereby irrevocably submits to the
exclusive jurisdiction of the New York Courts for the adjudication of any dispute hereunder or in connection herewith or with any
transaction contemplated hereby or discussed herein (including with respect to the enforcement of any of the Transaction Documents),
and hereby irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally
subject to the jurisdiction of such New York Courts, or such New York Courts are improper or inconvenient venue for such proceeding.
Each party hereby irrevocably waives personal service of process and consents to process being served in any such suit, action
or proceeding by mailing a copy thereof via registered or certified mail or overnight delivery (with evidence of delivery) to such
party at the address in effect for notices to it under this Debenture and agrees that such service shall constitute good and sufficient
service of process and notice thereof. Nothing contained herein shall be deemed to limit in any way any right to serve process
in any other manner permitted by applicable law. Each party hereto hereby irrevocably waives, to the fullest extent permitted by
applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to this Debenture or the
transactions contemplated hereby. If either party shall commence an action or proceeding to enforce any provisions of this Debenture,
then the prevailing party in such action or proceeding shall be reimbursed by the other party for its attorneys fees and other
costs and expenses incurred in the investigation, preparation and prosecution of such action or proceeding.



e)	Waiver.
Any waiver by the Company or the Holder of a breach of any provision of this Debenture shall not operate as or be construed to
be a waiver of any other breach of such provision or of any breach of any other provision of this Debenture. The failure of the
Company or the Holder to insist upon strict adherence to any term of this Debenture on one or more occasions shall not be considered
a waiver or deprive that party of the right thereafter to insist upon strict adherence to that term or any other term of this Debenture.
Any waiver by the Company or the Holder must be in writing.





18









f)	Severability.
If any provision of this Debenture is invalid, illegal or unenforceable, the balance of this Debenture shall remain in effect,
and if any provision is inapplicable to any Person or circumstance, it shall nevertheless remain applicable to all other Persons
and circumstances. If it shall be found that any interest or other amount deemed interest due hereunder violates the applicable
law governing usury, the applicable rate of interest due hereunder shall automatically be lowered to equal the maximum rate of
interest permitted under applicable law. The Company covenants (to the extent that it may lawfully do so) that it shall not at
any time insist upon, plead, or in any manner whatsoever claim or take the benefit or advantage of, any stay, extension or usury
law or other law which would prohibit or forgive the Company from paying all or any portion of the principal of or interest on
this Debenture as contemplated herein, wherever enacted, now or at any time hereafter in force, or which may affect the covenants
or the performance of this indenture, and the Company (to the extent it may lawfully do so) hereby expressly waives all benefits
or advantage of any such law, and covenants that it will not, by resort to any such law, hinder, delay or impede the execution
of any power herein granted to the Holder, but will suffer and permit the execution of every such as though no such law has been
enacted.



g)	Next
Business Day. Whenever any payment or other obligation hereunder shall be due on a day other than a Business Day, such payment
shall be made on the next succeeding Business Day.



h)	Headings.
The headings contained herein are for convenience only, do not constitute a part of this Debenture and shall not be deemed to limit
or affect any of the provisions hereof.



i)	Assumption. 
Any successor to the Company or any surviving entity in a Fundamental Transaction shall (i) assume, prior to such Fundamental Transaction,
all of the obligations of the Company under this Debenture and the other Transaction Documents pursuant to written agreements in
form and substance satisfactory to the Holder (such approval not to be unreasonably withheld or delayed) and (ii) issue to the
Holder a new debenture of such successor entity evidenced by a written instrument substantially similar in form and substance to
this Debenture, including, without limitation, having a principal amount and interest rate equal to the principal amount and the
interest rate of this Debenture and having similar ranking to this Debenture, which shall be satisfactory to the Holder (any such
approval not to be unreasonably withheld or delayed).  The provisions of this Section 9(i) shall apply similarly and equally
to successive Fundamental Transactions and shall be applied without regard to any limitations of this Debenture.



j)	Existence
of Class. Holder acknowledges and agrees by acceptance hereof that such Holder has been offered and sold this Debenture pursuant
to that certain subscription agreement dated [_____], 2012 (the “Subscription Agreement”) and that all such Holders
of Debentures offered and sold pursuant to the Subscription Agreement shall be part of and act as a class (the “Convertible
Debenture Holders”) for all purposes, including but not limited to any amendments, waivers or defaults. Any such action shall
require the affirmative consent of Holders of a twenty-five percent (25%) in outstanding aggregate principal amount of Debentures
sold to the Convertible Debenture Holders (except in the case of an Event of Default pursuant to Section 8(a)(i)(A)). All payments
made in connection with any Event of Default (except in the case of an Event of Default pursuant to Section 8(a)(i)(A)) or any
dissolution, winding up or other event of liquidation with respect to the Company shall be made pro rata to all Holders in proportion
to such Holder’s percentage interest of the aggregate principal amount of Debentures sold to the Convertible Debenture Holders.





19









k)	Subscription
Agreement. In connection with the issuance of this Debenture, the Holder has executed a Subscription Agreement and hereby acknowledges
and agrees that the representations and warranties made by the Holder in such Subscription Agreement shall be incorporated by reference
into this Debenture as if fully set forth herein.





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





(Signature Pages
Follow)







20





IN WITNESS WHEREOF,
the Company has caused this Debenture to be duly executed by a duly authorized officer as of the date first above indicated.





| | Spectrascience, Inc.                                                                                                                     
| | -----------------------------------------------------------------------------------------------------------------------------------------
| | By:__________________________________________
        Name:
        Title:
        Facsimile No. for delivery of Notices: _______________
| |                                                                                                                                          
| |                                                                                                                                          



21





ANNEX
A



NOTICE OF CONVERSION





The undersigned hereby
elects to convert principal under the 5% Original Issue Discount Convertible Debenture due ______ __, 2013 of Spectrascience, Inc.,
a Minnesota corporation (the “Company”), into shares of common stock (the “Common Stock”),
of the Company according to the conditions hereof, as of the date written below. If shares of Common Stock are to be issued in
the name of a person other than the undersigned, the undersigned will pay all transfer taxes payable with respect thereto and is
delivering herewith such certificates and opinions as reasonably requested by the Company in accordance therewith. No fee will
be charged to the holder for any conversion, except for such transfer taxes, if any.



By the delivery of
this Notice of Conversion the undersigned represents and warrants to the Company that its ownership of the Common Stock does not
exceed the amounts specified under Section 4 of this Debenture, as determined in accordance with Section 13(d) of the Exchange
Act.



The undersigned agrees
to comply with the prospectus delivery requirements under the applicable securities laws in connection with any transfer of the
aforesaid shares of Common Stock.



Conversion calculations:







| | Date to Effect Conversion:                                                                                                      
| | --------------------------------------------------------------------------------------------------------------------------------
| |                                                                                                                                 
| | Principal Amount of Debenture to be Converted:                                                                                  
| |                                                                                                                                 
| | Payment of Interest in Common Stock __ yes  __ no                                                                               
| | If yes, $_____ of                                                                                                               
| | Interest Accrued.                                                                                                               
| | Number of Conversion Shares payable on Principal or Interest that would exceed the limits set forth in Section 4(c) of the Note:
| |                                                                                                                                 
| | Number of shares of Common Stock to be issued:                                                                                  
| |                                                                                                                                 
| |                                                                                                                                 
| | Signature:                                                                                                                      
| |                                                                                                                                 
| | Name:                                                                                                                           
| |                                                                                                                                 
| | Address for Delivery of Common Stock Certificates                                                                               











22









Schedule 1



CONVERSION SCHEDULE



The 5% Original Issue Discount Unsecured
Convertible Debenture due on ____________, 2013 in the original principal amount of $____________ is issued by SpectraScience,
Inc., a Minnesota corporation. This Conversion Schedule reflects conversions made under Section 4 of the above referenced Debenture.



Dated:





|Date of Conversion
        (or for first entry, Original Issue Date) | Amount of Conversion | Aggregate Principal Amount Remaining Subsequent
        to Conversion
        (or original Principal Amount) | Company Attest
|-------------------------------------------------------------------- | -------------------- | ------------------------------------------------------------------------------------------------------------ | --------------
|                                                                     |                      |                                                                                                              |               
|                                                                     |                      |                                                                                                              |               
|                                                                     |                      |                                                                                                              |               
|                                                                     |                      |                                                                                                              |               
|                                                                     |                      |                                                                                                              |               
|                                                                     |                      |                                                                                                              |               
|                                                                     |                      |                                                                                                              |               
|                                                                     |                      |                                                                                                              |               
|                                                                     |                      |                                                                                                              |               









23









|Date of Conversion
        (or for first entry, Original Issue Date) | Amount of Conversion | Aggregate Principal Amount Remaining Subsequent
        to Conversion
        (or original Principal Amount) | Company Attest
|-------------------------------------------------------------------- | -------------------- | ------------------------------------------------------------------------------------------------------------ | --------------
|                                                                     |                      |                                                                                                              |               
|                                                                     |                      |                                                                                                              |               







24