AMENDED EMPLOYMENT AGREEMENT


                                     BETWEEN

                                  CENTREX, INC.

                                       AND

                                 JACK J. LUCHESE

         This Employment Agreement ("Agreement") is made and executed this 25th
day of March, 2003 and is effective upon satisfaction of the pre-conditions set
forth below (the "Effective Date"), by and between Centrex, Inc. ("Centrex" or
the "Company"), a Oklahoma Corporation having its principal place of business at
9202 South Toledo Avenue, Tulsa, OK 74137 and Jack J. Luchese ("Executive") who
currently resides at 116 Tranquility Lane, Destin, Florida 32541.

         WHEREAS, Centrex desires to recruit Executive as its new President and
Chief Executive Officer and Executive desires to be part of the challenge
offered by the Company and its technology platform.

         WHEREAS, the Centrex Board has authorized the execution of this
Agreement.

         WHEREAS, It is the intention of the parties that this Amended
Employment Agreement replace and supersede the Employment Agreement dated
January 21, 2003.

         NOW, THEREFORE, in consideration of the mutual covenants and promises
made in this Agreement, the parties do hereby agree as follows:

1. Employment, Responsibilities and Term:

         (a) Position Responsibilities:

         Centrex agrees to and does hereby engage and employ Executive initially
         as a consultant to the current CEO and upon completion of certain
         pre-requisites (as defined in Section 3. (c)) then the

<PAGE>

          Company's  new  President  and  Chief  Executive  Officer  of  Centrex
          Corporation  for the term and upon the terms and  conditions set forth
          herein, and Executive accepts such offer of employment. Executive will
          have  full  charge  chief  executive   responsibilities  that  include
          business  strategy   development,   research,   product   development,
          clinical,  regulatory,   manufacturing,  finance,  capital  formation,
          business development & licensing, human resources, investor relations,
          sales,  marketing,  administration,  and presenting information to the
          Board of Directors.


         (b) Term:
         The Term of the agreement will be three years commencing on the
         effective date of this Employment Agreement.

         (c) Board of Directors:
         It is also understood and agreed that Executive will serve as a
         Director of the Company, without additional compensation, for the
         appointed term. During the term of this Agreement, the Board of
         Directors will take such actions as may be required to appoint
         Executive for election as a director by the shareholders. Executive may
         serve on the Board of Directors of companies not affiliated with
         Centrex, and receive compensation in connection therewith, if such
         Board position is approved by the Board of Directors of Centrex. It is
         also recognized and agreed to that Executive is a Director of
         Angiogene, Inc. a medical device company in Montreal and will continue
         to serve on such Board and will be allowed to travel and participate in
         Board meetings during the year while employed by Company. Mr. Luchese
         also has some trailing responsibilities with DNA Print Genomics that he
         will be involved with occasionally through May 2003. The activities
         with these companies will not interfere with Mr. Luchese's ability to
         perform for Centrex and may even enhance and support his Centrex
         efforts.

          (d)     Commitment:
         Executive agrees to discharge his duties hereunder in accordance with
         the direction of the Board of Directors of Centrex and to follow
         diligently and implement faithfully all management policies and
         decisions communicated to him by the Board of Directors. During the
         employment of Executive by Centrex, Executive shall devote his full

                                       2
<PAGE>

          and undivided time,  attention,  energies and loyalty to the Company's
          business but the foregoing shall not be construed to prevent Executive
          from making investments in other businesses or enterprises or engaging
          in  any  other   business   activity  that  does  not  interfere  with
          Executive's  duties  under  this  Agreement,   or  conflict  with  his
          obligations  under  Paragraph  10  hereof  or  otherwise  represent  a
          conflict of interest with his duties to Centrex.

         (e)      Changes in Board and Officers:
         Concurrent with the execution of this agreement and also the closing of
         the next $2 million (net after fees and expenses) in financings the
         Executive will officially join the Company and will be elected
         President and CEO of Centrex and also Chairman of the Board by the
         current Centrex Board. The official start date is the date at which
         time the Executive assumes legal responsibilities for running the
         Company. Until the start date the Executive will continue to serve as a
         consultant to the current CEO and Board. It is also understood that the
         current Officers and Directors of Centrex will resign when Executive
         officially joins the Company with the execution of this agreement.
         Executive will be the sole Officer and Director and will be responsible
         for nominating a new Board of Directors and hiring a new management
         team.

2.       Term and Renewal. The term of Executive's employment hereunder will be
         for a period commencing on the Effective Date and continuing for a
         period of three (3) years (the "Expiration Date"), unless Executive's
         employment is terminated by either party pursuant to paragraph 6 of
         this Agreement. The agreement will automatically be renewed for another
         year if neither party provides the other with written notice of
         termination twelve (12) months in advance.

3.       Compensation Package and Relocation Reimbursement:

         (a) Starting Annual Salary:
         For services provided hereunder, Executive will be paid an annual base
         salary of Two Hundred Fifty Thousand Dollars ($250,000). Executive will
         initially operate the Company from his Florida location. Executive will
         be eligible for a salary review once each year on the anniversary of
         his employment agreement. It is understood that

                                       3
<PAGE>

          Executive is not entitled to any raise in salary but he is entitled to
          an annual  performance review and an annual review of his compensation
          package.  Any  salary  increases  during  the term will be at the sole
          discretion  of the Board but in no event will the base  salary be less
          than the initial amount during the Term.

         (b) Initial Start Up Period:
         Executive will begin full time employment with the Company on or around
         January 1, 2004. From Today's Date to January 1 Executive will provide
         consulting services as a non-employee to the Company at a 40%
         commitment and will be paid in cash at a rate consistent with his
         starting base salary plus all benefits and taxes. Accordingly,
         Executive will be paid $12,500 for April 2003. (40% of base salary +
         fringe benefits + employer payroll taxes + 40% of car allowance =
         approximately $12,500).

              Pre-conditions:
         The Company agrees to several employment pre-conditions as follows:

               -The outstanding payment obligations to the University of
                  California for the Los Alamos project for the months of
                  December through Executive's start date will be paid in full
                  when due.

               -In addition to the above the Company will raise a net minimum
                  of $2,000,000 (net of fees and expenses) cash to operate the
                  Company going forward until the next fundraising effort. The
                  Fifty Thousand Dollars the Executive invested for Preferred
                  Convertible Stock shall not count towards this $2,000,000.

              -The ceiling on authorized common shares will be raised above
                  the 45 million level to 250 million.

              -A non-cash  support  agreement  for the balance of 2003 with
                  Tom Coughlin and the Centrex Tulsa staff will be executed.

                                       4
<PAGE>

              -Completion, attachment and certification of financial schedules
                  as described in Section 23.

              -Change of Control Agreement

         (d)      Cash Bonus:
         It is understood and contemplated that, in addition to the foregoing
         annual base salary; Executive will be eligible to receive cash bonuses
         in each calendar year during the term of this Agreement in such
         amounts, if any, as shall be determined from time to time by a majority
         of independent Directors of the Company in their sole discretion. If
         this Agreement expires on the Expiration Date, then the obligation of
         the Company to pay a bonus to Executive on for the last year of
         service, if a bonus is approved, shall survive such expiration, and the
         Company shall pay such bonus to Executive as if this Agreement remained
         in full force and effect. The range of annual bonus payment may be from
         no bonus at all to 100% of Executive's then Base Salary for that year.
         However, the bonus, if approved by a majority of the independent
         Directors, for the first year will not be less than $50,000.

         (d) Headquarters Relocation Salary Adjustment:
         It is contemplated that the Board of Directors will request that
         Executive relocate to a geographical location more suitable to building
         and financing the Company. At the Board's request Executive will
         promptly relocate to such location. It is agreed that in the event the
         Company is moved to Atlanta such salary adjustment will be $15,000
         ($265,000 per year) annually and if in the Northeast such salary
         adjustment will be $25,000 ($275,000 per year). If such a relocation
         takes place Executive's base salary will be increased for the
         appropriate relocation allowance on the day Executive begins to conduct
         the business from the new location. If the Board chooses a location
         other than Atlanta or the Northeast the parties will agree on a
         reasonable base salary adjustment for the relocation.

         (e) Reimbursement of Household Relocation Costs:
         The Company will provide Executive with a $45,000 relocation allowance
         and the Company will provide a full federal, state and local income tax
         gross up on such relocation allowance so that the after tax

                                       5
<PAGE>

          cost to the Executive is less than $1,000.  This allowance is intended
          to  cover  the  move of  household  goods,  real  estate  commissions,
          mortgage points and closing costs on both homes.  The Company will pay
          half the  relocation  allowance on either the  execution of a purchase
          agreement  for a home in the  new  area  or the  sale  of his  current
          Florida home and the latter half upon the  Executive's  relocation  to
          the new area.

         (f) House Hunting and Temporary Living costs:
         In addition, the Company will reimburse Executive and his spouse for up
         to three house hunting visits and, if necessary, provide temporary
         living for up to six months.

         (g) Given the tax complexities as a result of a relocation during 2003
         the Company agrees to reimburse Executive for the professional services
         associated with filing his personal federal and state income taxes in
         2004 for the 2003 tax year.

4.       Fringe Benefits:
          Executive, during the period of his employment hereunder, will receive
         fringe benefits such as medical, dental, prescription drug and
         hospitalization insurance, vacation leave, short term sick leave and
         long term disability as well as participation in any retirement plan as
         may exist from time to time for all other executive officers of the
         Company; provided, however, that, during the term of this Agreement.
         The Company shall maintain at its expense a long-term disability policy
         for the benefit of Executive, which will provide coverage equal to
         Executive's Base Salary. Company will provide Executive an automobile
         and assume the cost of such car lease for business and his personal use
         including insurance and car maintenance while under contract with the
         Company. The purchase price level, before taxes, of the automobile to
         be leased will not exceed $40,000 and if it does exceed that amount
         Executive will contribute the incremental portion of the lease payment.
         In addition, the Company will provide reimbursement for certain
         communication devices such as cell phone, computer, PDA/Blackberry and
         related internet and other services that support such communication
         devices. Executive shall be entitled to four weeks of vacation leave,
         annually, which shall be paid at his then Base Salary, and shall accrue
         such

                                       6
<PAGE>

          vacation  time  and be  used  in  accordance  with  the  policies  and
          procedures of the Company.

5.       Reimbursement of Business Expenses:
         The Company will promptly reimburse Executive for all business expenses
         incurred by him in connection with the business of the Company in
         accordance with regular Company policy regarding the nature and amount
         of expenses and the maintenance and submission of receipts and records
         necessary for the Company to document them as proper business expenses.

6.       Termination of Employment and This Agreement.

(a) Termination for Cause or Voluntary Termination:
         If Executive's employment is terminated by the Company for cause (as
         hereinafter defined) or if Executive voluntarily leaves the employment
         of the Company prior to the Expiration Date, the Company will pay
         Executive the equivalent of three (3) months' salary at the Base
         Salary, and three (3) months continuation of fringe benefits then being
         received by Executive. For purposes of this Agreement, termination "for
         cause" means termination of Executive's employment by action of a
         majority of outside Directors of Centrex because of:

                  (1)      material breach of contract,

                  (2)      failure or inability to carry out legal directives of
                           the Board of Directors,

                  (3)      conviction of Executive for a felony, even if such
                           conviction is subject to appeal,

                  (4)      uncontroverted evidence of falsification of records
                           or statements of the Company,

                  (5)      uncontroverted evidence of intentional misuse of
                           Company funds or property, or

                                       7
<PAGE>

                  (6)      other substantial misconduct which, in the reasonable
                           judgment of the Board, results in material adverse
                           effect, discredit or disrepute to the Company.

                  A termination of employment for any cause listed in clauses
         (1), (2) or (6) above shall be effective only if Executive has first
         been given written notice by the Board of Directors of the alleged
         breach, failure to perform or misconduct and such breach, failure to
         perform or misconduct continues for fifteen days following the date of
         such notice.

(b) Termination for No Cause:
         If this Agreement expires on the Expiration Date, or if the sooner
         termination of Executive's employment and this Agreement is not for
         cause, not because of Executive's death or disability and not because
         of his voluntary termination of employment, then the Company will make
         a lump sum cash payment to Executive equal to one year of the
         Executive's then annual Base Salary, plus an average cash bonus for the
         last three years but not less than $50,000 and will provide twelve (12)
         months continuation of fringe benefits available to Executive and his
         dependents covered for such benefits at the time of Executive's
         Termination for No Cause. If it is not possible to cover Executive and
         his family with fringe benefits then the Company will make a lump sum
         payment to Executive for the value of such benefits. All the above lump
         sum payments will be paid immediately upon formal Termination for No
         Cause by the Board.

(c) Termination Due to Death:
         The Company will secure a term life insurance policy for the benefit of
         the Executive's estate in the amount of $1 million. Such insurance
         policy will promptly be put in place and will be maintained by Company
         during the full Term of this agreement including all extensions.

(d) Termination Due to Disability:
         The Company agrees to carry and pay for an individual long term
         disability policy on Executive of his choosing that covers his Base
         Salary plus bonus. The Company will continue to pay Executive his

                                       8
<PAGE>



          current  salary and continue to accrue his bonus until the  disability
          policy begins to pay Executive.

         It is understood that a permanently disabled status subject to long
         term disability shall mean such sickness, as well as physical or mental
         disability, that qualifies or, with the passage of time (not to exceed
         90 calendar days), will qualify Executive to receive benefit payments
         under at least one of the long-term disability policies maintained by
         the Company for Executive in accordance with Paragraph 4. In the event
         of a dispute as to Executive's ability to perform his duties, the
         Company may refer Executive to a licensed practicing physician of
         Centrex's choice and reasonably satisfactory to Executive, and
         Executive agrees to submit to such tests and examinations as such
         physician shall deem appropriate. The determination by the physician as
         to whether or not Executive is unable to perform substantially his
         normal duties shall conclusively determine such facts for the purposes
         of this Paragraph 7(c). Short term illness or injury not amounting to
         long term disability shall be treated in accordance with any benefit
         provided under Paragraph 4 of this Agreement.

7.       Centrex Repurchase Rights. If the Company fails to meet the
         pre-condition of raising the $2,000,000, the Company shall have the
         right to repurchase 50% of the preferred convertible stock (or Common
         Stock if the preferred is converted) for the purchase price paid. The
         right to repurchase shall last from January 1, 2004 until January 11,
         2004. The Preferred Convertible Shares are those granted in the
         Subscription Agreement dated March 24, 2003 between the Executive and
         the Company.

8.       No Restrictions on Executive's Employment by Centrex. Executive
         represents as a condition of this Agreement that he is not under any
         existing employment agreement, non-competition agreement or other
         legally binding agreement which would prohibit or in any manner
         restrict his employment hereunder with Centrex.


9.       Employee Confidentiality and Invention Assignment Agreement. Executive
         and the Company agree that the Employee shall keep all proprietary
         information confidential during employment and for two years after
         employee leaves his employment are parties to a

                                       9
<PAGE>

          confidentiality  and  invention   assignment  letter  agreement  dated
          ______________,  which  shall be deemed to be  incorporated  into this
          Agreement as if fully set forth in this Paragraph 9.

10.      Change of Control:
         Executive and the Company are parties to a Change of Control agreement
         dated January 21, 2003 ______________, which shall be deemed to be
         incorporated into this Agreement as if fully set forth in this
         Paragraph 10.

11.      Restrictions on Competition.

         (a) During Employment. In order to protect Centrex's investment, which
         includes but is not limited to, time, money, options and proprietary
         information, and in recognition of the unique character of the Trade
         Secrets and other Confidential Information which are the basis of
         Centrex's business and future business opportunities, in recognition of
         the worldwide geographic scope of Centrex's business and/or potential
         business opportunities and Executive's contemplated role,
         responsibilities and knowledge therefor, for the entire period of
         Executive's employment by Centrex, Executive agrees that he will not
         work as a consultant for or directly or indirectly perform services
         anywhere in the world for himself or any other person, firm or
         corporation in competition with Centrex. A business in competition with
         Centrex includes any business activity being actively investigated or
         contemplated by Centrex during the period of Executive's employment by
         Centrex. Without limitation on the foregoing, but by way of example,
         businesses currently contemplated by Centrex as being in competition
         with it include, but are not limited to, businesses engaged in or
         considering engaging in manufacture, marketing or development of lazer
         based Bioterrorism detection systems designed to detect airborne, water
         based and blood based pathogens as covered by Company patents.

         (b) For one two (1) (2) syear after termination of employment. In order
         to protect Centrex's investment, which includes but is not limited to,
         time, money and proprietary information and in recognition of the
         unique character of the Trade Secrets and other Confidential
         Information which are the basis of Centrex's business and future


                                       10
<PAGE>

         business opportunities, in recognition of the worldwide geographic
         scope of Centrex's business and/or potential business opportunities and
         Executive's contemplated role, responsibilities and knowledge therefor,
         for a period of two (2) years following the termination of Executive's
         employment with Centrex, regardless of the reason therefor, Executive
         agrees that he will not work as a consultant for or directly or
         indirectly perform services anywhere in the world for himself or any
         other person, firm or corporation in any capacity involving the study,
         development, use, manufacture or marketing of products covered by
         Centrex patents.

                  The foregoing shall not preclude (1) the employment of
         Executive, whether as a director, officer, employee, consultant or
         otherwise, by a research partner, joint venture partner, licensee or
         other person, or corporation or entity that at such time is authorized
         by Centrex to have rights in or to restricted products, or (2) the
         ownership by Executive of investment securities representing not more
         than three (3) per cent of the outstanding voting securities of company
         engaged in a pharmaceutical business, whose stock and/or securities are
         traded on a national stock exchange or national quotations system,
         provided that such investment is passive and not with the intention of
         controlling such business.

         (c) Executive agrees and acknowledges that the restrictions on
         competition contained herein including their geographic and product
         scope are necessary and reasonable to protect the interests of Centrex
         and that the Company's Trade Secrets and other Confidential Information
         of which he will become acquainted, if used anywhere in the world
         during the period in which he has agreed not to use them or to disclose
         them would cause Centrex serious and irreparable damage and harm.
         Executive represents and admits that upon the termination of his
         employment with Centrex, his experience and capabilities are such that
         he can obtain employment engaged in other lines of endeavor and that
         the enforcement of this Agreement would not prevent him from earning a
         livelihood.


                                       11
<PAGE>

12.      Acknowledgments.

                  (a) It is understood and contemplated by the parties that if
         the obligations undertaken herein in Paragraphs 9 and 10 were breached
         in any way, irreparable harm to the Company should be presumed. Damages
         might be difficult if not impossible to ascertain, and the faithful
         observance of the terms of this Agreement during and after termination
         of Executive's employment is an essential condition to his employment
         with the Company. In light of these considerations, Executive agrees
         that a court of competent jurisdiction may immediately enjoin any
         breach or threatened breach of Paragraphs 9 and 10 to this Agreement,
         without waiver of any other rights and remedies which the Company may
         have at law.

                  (b) The obligations undertaken in Paragraphs 9 and 10 of this
         Agreement survive the termination of Executive's employment hereunder
         for the period specified in each such Paragraph and the termination of
         this Agreement, regardless of the reason therefor.

                  The obligations of Centrex to Executive following his
         termination of employment as set forth in Paragraphs 3(b), and 6 shall
         survive the termination of this Agreement until satisfied in accordance
         with the terms thereof.

                  (c) The rights of Executive under this Agreement are in
         addition to any other rights or remedies he may have in law or in
         equity in the event Centrex breaches this Agreement, all of which
         rights and remedies are preserved in full. Without limiting the
         foregoing, the rights of Executive under Paragraph 6 herein do not
         limit any right he would have upon termination of employment caused by
         a breach of Centrex. However, any damages he may sustain shall be
         reduced by the payments required to be made under this Agreement.

13.      Construction of Agreement.

                  (a) It is the intention of the parties to this Agreement that
         any construction of this Agreement or Paragraph thereof shall be in
         favor of its legality and enforceability and that any construction
         causing


                                       12
<PAGE>

          illegality or unenforceability should yield to a construction favoring
          legality and  enforceability.  Further,  the parties agree that should
          any  portion  of  this   Agreement   be   judicially   held   invalid,
          unenforceable  or void,  such  holding  shall  not have the  effect of
          invalidating or voiding any remaining portion of this Agreement not so
          declared  and that any portion  held to be invalid,  unenforceable  or
          void  shall,  if  possible,  be deemed  amended  or  reduced in scope,
          otherwise to be stricken from this  Agreement,  but only to the extent
          required  for  purposes of  maintaining  the  legality,  validity  and
          enforceability  of this  Agreement  and all  portions  thereof  in the
          jurisdiction so holding.

                  (b) It is understood that use of the word "and" herein
         included the disjunctive as well as its injunctive meaning whenever
         such meaning would broaden the protection to the Company in the context
         in which it is used.

14.      No Waiver. No waiver of any breach of this Agreement may be construed
         or deemed as a waiver of any succeeding breach of this Agreement.

15.      Personal Services. It is understood and contemplated that this
         Agreement provides for personal services of Executive to the Company.

16.      No Interference. For two (2) years following the termination of
         Executive's employment hereunder, regardless of the reason therefor,
         Executive will not intentionally disrupt or attempt to disrupt the
         Company's business relationship with its customers or suppliers, nor
         solicit any of the Company's employees to terminate their employment
         with Centrex.

17.      Certification by Employee. Executive certifies that he has received a
         copy of this Agreement for review and study before being asked to
         execute it, that he has read this Agreement carefully, that he has had
         a sufficient opportunity before executing this Agreement to ask
         questions about it and to receive answers to any such questions and
         that he understands the obligations and rights provided hereunder.

                                       13
<PAGE>

18.      Entire Agreement. This Agreement hereto supersedes any and all other
         agreements, both oral and in writing, between the parties hereto with
         respect to the employment and terms and conditions thereof of Executive
         by Centrex, and it contains all of the parties' representations,
         covenants and agreements with respect to such matters. The terms of
         this Agreement may not be changed orally but only by a subsequent
         writing signed by the party against whom enforcement of such
         modification is sought.

19.      Captions. Paragraph captions used herein are for convenience of
         reference only and shall not change the meaning of the terms of this
         Agreement.

20.      Successors and Assigns. The terms of this Agreement shall inure to the
         benefit of any successors and assigns of the Company.

21.      Governing Law and Venue. This Agreement shall be construed and governed
         in accordance with the laws of the State of Oklahoma. The parties agree
         venue shall be proper solely in the state and federal courts in
         Oklahoma.

22.      Corporate Authority. The Company represents and warrants that this
         Agreement (1) constitutes a legal, valid and binding obligation of the
         Company enforceable in accordance with its terms, and (2) does not
         conflict with or result in a violation of the Company's Certificate of
         Incorporation, By-laws, or any contract, agreement or instrument to
         which the Company is a party or is otherwise bound.

23.      Debt Conversion/Capitalization Table/Budget Certification:
         A number of financial schedules have been prepared to fully disclose
         the Company's finances and to enable the parties to calculate
         Executive's incentive stock grant. As of the date Executive begins full
         time employment with the Company, the CFO has prepared and certified
         the attached monthly "bare bones" budget of expenses for 2003 (schedule
         A), a monthly cash flow forecast by month for the balance of 2003
         (schedule B), a detailed schedule of all payables and accruals
         (schedule C) outstanding, a pre-Executive conversion of preferred
         shares Capitalization Table showing all major individual shareholders
         and derivative holders along with the allowance made to

                                       14
<PAGE>

          raise  additional  cash  and  provide  for  Executives  conversion  of
          Preferred Convertible Shares (schedule D).

24.      Advice of Counsel:
          The parties to this Agreement have the opportunity to seek advice of
         counsel prior to executing this Agreement.

25.      Jointly Prepared:
         As this document is the result of extensive negotiation by the parties,
         it shall be deemed to be jointly written and prepared by the parties.

                                       15
<PAGE>




         IN WITNESS WHEREOF, the parties hereto have executed this Agreement
under seal on the date hereof, to be effective as of the Effective Date.

JACK J. LUCHESE:

/s/ Jack J. Luchese
----------------------------
(an individual)

CENTREX, INC.:


By: /s/ Thomas R. Coughlin, Jr.
-------------------------------
Thomas R. Coughlin, Jr., M.D.
President and CEO

Attest:
CENTREX, INC.


By: /s/ Thomas R. Coughlin, Jr.
-------------------------------
Corporate Secretary



(CORPORATE SEAL)