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                                                                   EXHIBIT 10.41

           AMENDMENT NO. 1 TO EMPLOYMENT AGREEMENT DATED JULY 1, 1998
                             WITH THAT T. NGO, PH.D.

                     AMENDMENT NO. 1 TO EMPLOYMENT AGREEMENT

        This AMENDMENT NO. 1 TO EMPLOYMENT AGREEMENT (this "Amendment"), is
entered into as of July 1, 1998, by and between AMDL, Inc. (the "Company") and
That T. Ngo, Ph.D. ("Employee"), to amend that certain Employment Agreement,
executed as of October 1, 1996 ("1996 Agreement" and together with this
Amendment, the "Agreement"), between the aforesaid parties.

                                 R E C I T A L S

        WHEREAS, pursuant to Section 4(a) of the 1996 Agreement, the Employee is
entitled to a base salary of $18,500 per month ("Base Salary"); and

        WHEREAS, the Company and the Employee desire to amend Section 4(a) of
the 1996 Agreement so as to defer one-half (1/2) of the Base Salary to be paid
from a portion of equity funding proceeds;

                                A G R E E M E N T

        1. Section 4, paragraph (a) of the 1996 Agreement is hereby amended to
read as follows:

               (a) Base Compensation. During the term of this Agreement, the
        Company agrees to pay Employee a base salary at the rate of $18,500 per
        month ("Base Salary"). One-half (1/2) of such Base Salary, in the amount
        of $9,250.00, shall be payable in accordance with the Company's
        practices from time to time. The payment of the remaining one-half (1/2)
        of the Base Salary, in the amount of $9,250.00, shall be deferred
        commencing on July 15, 1998, accruing interest at the rate of 8.50% per
        annum until the payment of such deferred Base Salary ("Deferred
        Salary").

               The Company agrees to pay Deferred Salary from ten percent (10%)
        of equity funding proceeds received in excess of $500,000.00 ("Available
        Equity Proceeds"). As of the date of this Amendment, the Company will
        agree to pay certain other deferred salary from Available Equity
        Proceeds. Accordingly, in the event that Available Equity Proceeds are
        insufficient to pay all of the outstanding deferred salary, Employee
        shall receive a pro rated amount of Deferred Salary consisting such
        amount as the Available Equity Proceeds compares to the total deferred
        salary intended to be paid from Available Equity Proceeds.

        2. Other than as specifically provided in this Amendment, all other
provisions of the 1996 Agreement shall remain effective.

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

                                         "COMPANY"

                                         AMDL, INC.,
                                         a Delaware corporation


                                         By: /s/ HARRY BERK
                                             -----------------------------------
                                             Harry Berk, Chief Financial Officer

                                         EMPLOYEE:


                                         By:  /s/ THAT T. NGO, PH.D.
                                         ---------------------------------------
                                                  That T. Ngo, Ph.D.


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