EXHIBIT A

                                 PLAN OF MERGER

     THIS PLAN OF MERGER (this "Plan of Merger"),  dated as of March 6, 2000, is
among  Pathobiotek  Diagnostics,  Inc.,  a  Texas  corporation  ("Parent"),  and
Investra Enterprises,  Inc., a Florida corporation (the "Company") (collectively
"Constituent Corporations").

          WHEREAS, Parent owns 100% of the shares of the Company and the parties
thereto have agreed to the merger of the Company with and into Parent; and

          WHEREAS,   Parent,  as  the  sole  shareholder  of  Company  and,  the
respective  Boards of Directors of Parent and the  Company,)  have each approved
the merger of the Company  into  Parent in  accordance  with the Texas  Business
Corporation Act (the "TBCA") and

         WHEREAS,  this Plan of Merger  shall be filed with  Articles  of Merger
with the  Secretaries  of State of Florida and Texas in order to consummate  the
merger of the Company with and into Parent; and

          WHEREAS,  Parent and the Company  have agreed to execute and file this
Plan of Merger as provided under the Florida Law and the TBCA.

          NOW,  THEREFORE,  in  consideration  of the  premises  and the  mutual
covenants herein contained, Parent and the Company hereby agree as follows:

         1. THE  MERGER.  At the  Effective  Time (as  defined  in  Section  1.3
hereof),  in accordance with this Plan of Merger,  and Florida Law and the TBCA,
the  Company  shall be merged  (such  merger  being  herein  referred  to as the
"Merger") with and into the Parent,  the separate existence of the Company shall
cease,  and  Parent  shall  continue  as  the  surviving   corporation.   Parent
hereinafter sometimes is referred to as the "Surviving Corporation."

          2.  EFFECT OF THE  MERGER.  When the  Merger  has been  effected,  the
Surviving Corporation shall retain the name "Pathobiotek Diagnostics, Inc."; and
the Surviving Corporation shall thereupon and thereafter possess all the rights,
privileges,  powers and  franchises of a public as well as of a private  nature,
and be subject to all the  restrictions,  disabilities and duties of each of the
Corporations;   and  all  and  singular,  the  rights,  privileges,  powers  and
franchises  of each of the  Constituent  Corporations  and all  property,  real,
personal and mixed,  and all debts due to either of the Corporations on whatever
account,  as well for  stock  subscriptions  as all  other  things  in action or
belonging  to  each  of such  corporations  shall  be  vested  in the  Surviving
Corporation;  and all property, rights,  privileges,  powers and franchises, and
all and every other interest shall be thereafter as effectually  the property of
the Surviving Corporation as they were of the Constituent Corporations,  and the
title to any real estate vested by deed or otherwise, in any of such Constituent
Corporations,  shall  not  revert  or be in any way  impaired  by  reason of the
Merger;  but all rights of  creditors  and all liens upon any property of any of
said  Constituent  Corporations  shall be preserved  unimpaired,  and all debts,
liabilities  and  duties  of  the  respective  Constituent   Corporations  shall
thenceforth attach to the Surviving Corporation,  and may be enforced against it
to the same extent as if said debts, liabilities and duties had been incurred or
contracted by it.

         3. CONSUMMATION OF THE MERGER. The parties hereto will cause the Merger
to be  consummated by filing with the Secretary of State of Florida and Texas an
articles  of merger  and this Plan of Merger in such form as  required  by,  and
executed in accordance with, the relevant  provisions of the Florida Law and the
TCBA (the time of such filing  being the  "Effective  Time" and the date of such
filing being the "Effective Date").

     4. ARTICLES OF INCORPORATION:  BYLAWS: DIRECTORS AND OFFICERS. The Articles
of Incorporation and bylaws of the Surviving Corporation shall be identical with
the Articles of Incorporation and bylaws of the Parent as in effect  immediately
prior to the  EffectiveTime  until  thereafter  amended as provided  therein and
under the Texas Law.

     5. CONVERSION OF SECURITIES. At the Effective Time, by virtue of the Merger
and without  any action on the part of Parent,  the Company or the holder of any
of the shares  (the  "Shares")  of common  stock,  (the  "Common  Stock") of the
Company:


          (a)  Each  Share  issued  and  outstanding  immediately  prior  to the
Effective  Time shall  remain as issued and  outstanding  common stock of parent
without change.

          (b) Each Share  which is held in the  treasury of the Company or which
is owned by any direct or indirect  subsidiary  of the Company shall be canceled
and retired, and no payment shall be made with respect thereto.

          (c) Each  outstanding  or authorized  subscription,  option,  warrant,
call, right (including any preemptive right),  commitment, or other agreement of
any character  whatsoever which obligates or may obligate the Parent to issue or
sell any additional  shares of its capital stock or any  securities  convertible
into or evidencing the right to subscribe for any shares of its capital stock or
securities  convertible  into or  exchangeable  for such shares,  if any,  shall
remain unchanged.

          (d) Each  share of Common  Stock,  of Company  issued and  outstanding
immediately  prior to the Effective Time shall be retired into treasury,  of the
Surviving Corporation.

          (e) No  Fractional  Shares  and no  certificates  or scrip
representing  such  fractional  Merger Shares, shall be issued:

          6. TAKING OF NECESSARY ACTION:  FURTHER ACTION.  Each of Parent, and
the Company shall use all reasonable  efforts to take all such actions as may be
necessary or  appropriate  in order to  effectuate  the Merger under the Florida
Law, the TCBA or federal law as promptly as possible.  If, at any time after the
Effective  Time,  any further  action is necessary or desirable to carry out the
purposes of the Agreement and to vest the Surviving Corporation with full right,
title and possession to all assets,  property,  rights,  privileges,  powers and
franchises of either of the Constituent Corporations, the officers and directors
of the  Surviving  Corporation  are  fully  authorized  in  the  name  of  their
corporation  or otherwise to take, and shall take, all such lawful and necessary
action.

     IN WITNESS WHEREOF,  Parent,  Parent, and the Company have caused this Plan
of Merger to be executed as of the date first above written.

                      INVESTRA ENTERPRISES, INC.
                      (A Florida corporation)

                      By:/s/Scott Deitler



                      PATHOBIOTEK DIAGNOSTICS, INC.
                      (A Texas corporation)


                       By:/s/Paul Enright
                       Paul Enright by Power of Attorney


<PAGE>


                               ARTICLES OF MERGER

                                       OF

                          PATHOBIOTEK DIAGNOSTICS, INC.
                              (A Utah Corporation)

                                      INTO

                          PATHOBIOTEK DIAGNOSTICS, INC.
                              (A Texas Corporation)

Filed in the Office of the
Secretary of State of the
State of Texas

Jan 05 1999
No.: C30645-98
Dean Heller, Secretary of State

     The Undersigned,  being sole Director of Pathobiotek  Diagnostics,  Inc., a
Utah corporation,  and the sole officer and director of Pathobiotek Diagnostics,
Inc., a Texas corporation, hereby certify as follows:

     1. A merger for the purpose of changing  domicile has been  approved by the
board of directors of Pathobiotek  Diagnostics,  Inc., a Utah  corporation,  and
Pathobiotek Diagnostics, Inc., a Texas corporation.

     2.  Shareholders  owning  5,100,000  of  the  shares  of  common  stock  of
Pathobiotek Diagnostics,  Inc., a Utah corporation,  which number of shares is a
majority of the approximately  8,223,373 shares  outstanding,  voted in favor of
such  merger  on  December  14,  1998.  The  sole   shareholder  of  Pathobiotek
Diagnostics,  Inc.,  a Texas  corporation,  voted  for such  plan of  merger  on
December 31, 1998.

     3.  A  Notice,  including  a  summary  of the  merger,  was  mailed  to all
shareholders of the Utah Corporation on or about November 30, 1998.

     4. Sheridan  Industries,  Inc., a Texas corporation,  hereby agrees that it
will prmptly pay to the dissenting shareholders, if any, of Sheridan Industries,
Inc., a Utah  corporation,  the amount,  if any, to which they shall be entitled
under the provisions of the Utah Corporation Statutes with respect to the rights
of dissenting shareholders.

         EFFECTIVE THE 31ST day of December, 1998

Pathobiotek Diagnostics, Inc.                    Pathobiotek Diagnostics, Inc.
A Utah corporation                               A Texas corporation

BY:/S/ROBERT KROPF                               BY:/S/ROBERT KROPF
Robert Kropf, President/Secretary                Robert Kropf,
                                                 President/Secretary


<PAGE>


State of Utah                       )
                                    )ss.
County of Salt Lake City            )

         ON  THIS  4TH  day of  January,  1999,  before  me,  a  Notary  Public,
personally  appeared  Robert  Kropf,  and  executed  on this date the  foregoing
instrument for the purposes therein contained, by signing on behalf of the above
named corporations as a duly authorized director and officer.

         IN WITNESS WHEREOF, I have hereunto set my hand and official seal.

                                    /S/JENNIFER L. CLARK

                                    Notary Public
                                    Residing at: Salt Lake

My Commission Expires:
7-1-02


<PAGE>


                           NOTICE OF A SPECIAL MEETING

                             OF THE SHAREHOLDERS OF

                          PATHOBIOTEK DIAGNOSTICS, INC.

     The Board of Directors of Pathobiotek Diagnostics, Inc., a Utah corporation
("the  Company"),  hereby give notice that a special meeting of the shareholders
of record,  as of December 1, 1998,  is called and will be held on December  14,
1998, at 8:00 a.m. at 4505 South Wasatch Blvd., Suite 21, Salt Lake City, Utah.

         The purpose of the meeting is to  authorize  the Board of  Directors to
effect a 120 to 1 reverse  split of the  Company's  common  stock,  authorize  a
change of the  Company's  domicile  from Utah to Texas,  and any other  matters,
which come before the shareholders.

         PLAN OF MERGER:  The Company will form a Texas subsidiary to effectuate
a change of corporate  domicile.  Following the reverse split,  the shareholders
shall receive one share of the Texas Corporation for each share of the Company.

         Any  shareholders,  who will be voting  through a proxy,  must have the
person  representing  them at the  meeting  present a copy of a signed and dated
proxy statement when they arrive at the meeting.

         Your proxy is not being solicited by the Board of Directors.

         DATED THIS 30TH day of November, 1998.

                                    By Order Of:


                                    The Board of Directors