Exhibit 10.24

                      FIRST MODIFICATION OF LOAN AGREEMENT


                  THIS FIRST  MODIFICATION is made as of this 30th day of April,
1999, by and between  IMMUCOR,  INC., a Georgia  corporation  ("Borrower"),  and
WACHOVIA BANK, N.A., a national banking association ("Lender").

                               Statement of Facts

                  Lender  and   Borrower   are  parties  to  that  certain  Loan
Agreement,  dated as of October  27,  1998 (the "Loan  Agreement"),  pursuant to
which  Lender  has  agreed  to make one or more  loans  from time to time to the
Borrower  in  accordance  with the  terms and  conditions  thereof.  Lender  and
Borrower desire to modify the Loan Agreement in certain  respects,  and Borrower
has  requested  that Lender grant certain  consents and waivers  relating to the
Loan  Agreement,  all in accordance with and subject to the terms and conditions
set forth herein.

                  NOW,  THEREFORE,   in  consideration  of  the  premises,   the
covenants  and  agreements   contained  herein,  and  other  good  and  valuable
consideration,  the  receipt  and  adequacy  of which are  hereby  acknowledged,
Borrower and Lender do hereby agree that all capitalized terms used herein shall
have the meanings  ascribed  thereto in the Loan Agreement  (except as otherwise
expressly defined or limited herein) and do hereby further agree as follows:

                               Statement of Terms

                  1.  Consents.  Subject to the  fulfillment  of the  conditions
precedent to the  effectiveness of this First  Modification  which are set forth
below, Lender hereby consents to the following actions of Borrower:

(a) (i) the acquisition by Borrower of the assets of the BCA Division ("BCA") of
Biopool  International,  Inc., a Delaware  corporation,  and the  formation  and
organization by Borrower of BCA Acquisition  Corporation,  a Georgia corporation
("BCA  Acquisition")  which will be a  wholly-owned  subsidiary  of Borrower and
which will acquire the assets of BCA;  (ii) the  acquisition  by Borrower of its
Belgian  distributor  Medichim,  S.A.,  a  company  organized  under the laws of
Belgium ("Medichim");  (iii) the indirect acquisition of Immunochim, s.a.r.l., a
company  organized under the laws of France  ("Immunochim")  and a subsidiary of
Medichim;  and (iv) the formation and organization of Immucor Acquisitions Inc.,
S.A. ("Immucor  Acquisitions") for the purpose of acquiring the capital stock of
Medichim; and

(b) the dissolution of Delta Diagnostics,  Inc., a Texas corporation  ("Delta"),
which was an indirect Subsidiary of Borrower.

                  2.  Waivers.  Subject  to the  fulfillment  of the  conditions
precedent to the  effectiveness of this First  Modification  which are set forth
below,  Lender hereby waives any Default or Event of Default under the following
sections  of the Loan  Agreement,  as  amended  by the  amendments  set forth in
Section 3 herein, which may arise from the following actions of Borrower:

(a) any  Default  or Event of  Default  under  Section  5.9 which may arise from
Borrower's (i) acquisition of the assets of BCA, (ii) formation and organization
of BCA  Acquisition to hold the assets and assume the  liabilities of BCA, (iii)
acquisition of Medichim and (iv) the creation of Immucor Acquisitions to acquire
the capital stock of Medichim; and

(b) any Default or Event of Default  under Section 4.6 and Section 5.7 which may
arise from Borrower's dissolution of Delta.

                  3. Amendments of Loan Agreement. Subject to the fulfillment of
the conditions  precedent to the effectiveness of this First  Modification which
are set forth  below,  the Loan  Agreement  shall be amended from and after this
date as follows:

(a) The Loan  Agreement is hereby amended by deleting the definition of the term
"Line of Credit  Limit" in  Section  1.1  thereof  and by  substituting  in lieu
thereof the following new definition of such term:

"Lineof Credit Limit" shall mean  $5,000,000,  subject to reduction  pursuant to
Section 2.1.1.

(b) The Loan Agreement is hereby amended by adding the following new sentence at
the end of Section 2.1.1 thereof:

                  Notwithstanding  anything herein to the contrary,  the Line of
                  Credit Amount shall be reduced on each date shown below to the
                  amount shown  opposite  such date below,  all without  further
                  action by Borrower or Lender:

                                  Reduction Date           Line of Credit Limit

                             December 31, 1999                   $4,800,000
                             March 31, 2000                      $4,600,000
                             June 30, 2000                       $4,400,000
                             September 31, 2000                  $4,200,000
                             December 31, 2000                   $4,000,000
                             March 31, 2001                      $3,800,000
                             June 30, 2001                       $3,600,000
                             September 30, 2001                  $3,400,000
                             December 31, 2001                   $3,200,000
                             March 31, 2002                      $3,000,000

(d) The Loan  Agreement  is hereby  amended by  deleting  the first  sentence of
Section 2.1.3.  therein in its entirety and by  substituting in lieu thereof the
following new first sentence of Section 2.1.3.:

                           "During the period from the Closing  Date through the
                  Additional Term Loan Commitment  Termination Date, and subject
                  to the terms and conditions of this  Agreement,  Lender agrees
                  to make the Additional Term Loans to Borrower, the proceeds of
                  which  shall  be  used  by  Borrower  solely  to  finance  its
                  repurchase  from time to time of shares of its common stock as
                  permitted by Section 5.5 hereof and to finance its purchase of
                  all of the  outstanding  stock of Medichim  and to finance the
                  purchase of substantially all of the assets of the BCA"

(e) The Loan  Agreement  is hereby  amended by adding to the end of Section  5.2
therein the following new sentence:

                            "Notwithstanding the foregoing, a Credit Party shall
                  be permitted  to cause  letters of credit to be issued for the
                  benefit of any  creditor  of any  Excluded  Subsidiary  to the
                  extent  permitted by Section 5.13 of this  Agreement,  and BCA
                  Acquisition  shall be permitted  to assume the trade  payables
                  and other current  liabilities  of BCA in connection  with its
                  acquisition of the assets of BCA."

(f) The Loan  Agreement  is  hereby  amended  by  deleting  the  "and"  prior to
subsection  (iii) of Section  5.9 and by adding to the end of such  section  the
following new subsection:

                  "; and (iv) the creation by Borrower of Immucor  Acquisitions,
Inc.,   S.A.,  a  company   organized  under  the  laws  of  Belgium   ("Immucor
Acquisitions")."

(g) The Loan Agreement is hereby amended by deleting Section 5.13 therein in its
entirety and by substituting in lieu thereof the following new Section 5.13:

                            "5.13 Excluded  Subsidiaries.  No Credit Party shall
                  make any capital contribution, loan or advance to any Excluded
                  Subsidiary  or transfer any assets to any Excluded  Subsidiary
                  or cause to be issued any letter of credit for the  benefit of
                  any creditor of any Excluded Subsidiary provided, however that
                  a  Credit   Party   shall  be   permitted   to  make   capital
                  contributions,  loans or advances to any Excluded  Subsidiary,
                  or transfer any assets to any Excluded  Subsidiary or cause to
                  be issued letters of credit for the benefit of any creditor of
                  any Excluded  Subsidiary  so long as the  aggregate  amount of
                  such  transactions does not exceed US $1,500,000 in any Fiscal
                  Year and so long as no Default  Condition  or Event of Default
                  exists or would be caused thereby."

(h) The Loan  Agreement is hereby  amended by deleting  Schedule  3.4,  Schedule
3.15,  Schedule 3.16,  Schedule 5.1 and Schedule 5.2 thereof in their entireties
and by  substituting  in lieu thereof the following  new Schedule 3.4,  Schedule
3.15,  Schedule  3.16,  Schedule  5.1  and  Schedule  5.2  attached  hereto  and
incorporated herein and therein by reference, respectively.

                  4.  Delivery  of  Stock  Pledge   Agreements   and  Additional
Documents.  The Borrower  shall have until May 7, 1999 to deliver the  following
documents:

(a) the Stock Pledge  Agreements  from (i) Gamma  Biologicals,  Inc. in favor of
Lender covering 65% of the shares of Gamma Biologicals B.V., a company organized
under the laws of The  Netherlands  ("Gamma  B.V.");  (ii)  Borrower in favor of
Lender  covering  66% of the  shares  of  Immucor  Trading  Company,  a  company
organized  under the laws of Barbados  ("Immucor  Trading");  (iii)  Borrower in
favor of Lender  covering  66% of the  shares of Immucor  Acquisitions  and (iv)
Borrower  in favor of  Lender  covering  all of the  shares  of BCA  Acquisition
(collectively, the "Stock Pledge Agreements"); and

(b) the closing documents from Gamma B.V., Gamma International, Immucor Trading,
Immucor  Acquisitions  and BCA  Acquisition  of the types  described in Sections
10.1.4,  10.1.5 and 10.1.6 of the Loan  Agreement  (collectively,  the  "Closing
Documents").

                  5. No Other  Amendments,  Consents or Waivers.  Except for the
consents, waivers and amendments expressly set forth and referred to in Sections
1 and 3 above,  the Loan Agreement shall remain  unchanged and in full force and
effect.  Nothing in this First Modification is intended,  or shall be construed,
to constitute a novation or an accord and  satisfaction of any of the Borrower's
indebtedness or other indebtedness to the Lender under or in connection with the
Loan Agreement (collectively,  the "Obligations") or to modify, affect or impair
the perfection or continuity of Lender's security  interests in, security titles
to or other  liens on any  collateral  for the  Obligations.  The  consents  and
waivers granted herein are given on a one-time basis only, and nothing contained
herein  shall  be  deemed  to  permanently  modify  the  provisions  of the Loan
Agreement whether through course of dealing, course of conduct or otherwise.

                  6.  Representations and Warranties.  To induce Lender to enter
into this First  Modification,  the Borrower does hereby warrant,  represent and
covenant to Lender that: (a) each representation or warranty of the Borrower set
forth in the Loan  Agreement  is  hereby  restated  and  reaffirmed  as true and
correct on and as of the date hereof as if such  representation or warranty were
made  on and  as of  the  date  hereof  (except  to the  extent  that  any  such
representation  or  warranty  expressly  relates  to a  prior  specific  date or
period), and no Default or Event of Default has occurred and is continuing as of
this date under the Loan  Agreement as amended by this First  Modification;  and
(b) Borrower  has the power and is duly  authorized  to enter into,  deliver and
perform this First  Modification and this First Modification is the legal, valid
and binding obligation of Borrower enforceable against it in accordance with its
terms.

                  7.  Conditions   Precedent  to  Effectiveness  of  this  First
Modification.  The  effectiveness  of this First  Modification and the consents,
waivers and amendments  provided herein are subject to the truth and accuracy in
all material  respects of the  representations  and  warranties  of the Borrower
contained in Section 6 above and to the fulfillment of the following  additional
conditions precedent: (a) Lender shall have received one or more counterparts of
this First Modification duly executed and delivered by the Borrower;  (b) if and
to the extent  required by Lender,  any and all  guarantors  of the  Obligations
shall have  consented to the execution,  delivery and  performance of this First
Modification and all of the transactions  contemplated  hereby by signing one or
more counterparts of this First  Modification in the appropriate space indicated
below and returning same to Lender;  (c) Lender shall have received the executed
Stock Pledge  Agreements  described in Section 4(a) above in form and  substance
satisfactory  to  Lender;  (d)  Lender  shall  have  received  a  fully  earned,
non-refundable  additional loan origination fee of $11,250;  (e) BCA Acquisition
and Gamma  International  shall have  executed a guaranty  agreement in form and
substance  satisfactory to Lender guaranteeing  Borrower's Obligations under the
Loan  Agreement;  and (f) Lender shall have received a  replacement  Master Note
dated as of the date of this  Modification  and having a stated principal amount
equal  to the  Line  of  Credit  Limit  as  amended  by this  Modification  (the
"Replacement  Master Note") as well as a closing  certificate of Borrower and an
opinion  of  Borrower's  counsel  (both in form and  substance  satisfactory  to
Lender) with respect to this Modification and the Replacement Master Note.

                  8.  Counterparts.  This First  Modification may be executed in
multiple  counterparts,  each of which shall be deemed to be an original and all
of which when taken together shall constitute one and the same instrument.

                  9.  Governing Law. This First  Modification  shall be governed
by, and construed in accordance  with, the internal laws of the State of Georgia
applicable to contracts made and performed in such state.

                  IN WITNESS WHEREOF,  the parties hereto have caused this First
Modification  to be duly executed and delivered as of the day and year specified
at the beginning hereof.

                                       BORROWER:

                                       IMMUCOR, INC.


                                       By:      /s/ Edward L. Gallup
                                               Edward L. Gallup, President


                                       LENDER:

                                       WACHOVIA BANK, N.A.


                                       By:      /s/ Ernesto Moran
                                       Title:   President




<PAGE>


                              CONSENT OF GUARANTORS


                  Each of the undersigned  guarantors does hereby consent to the
execution,   delivery  and   performance  of  the  within  and  foregoing  First
Modification of Loan Agreement.

                  IN WITNESS  WHEREOF,  each of the  undersigned  guarantors has
executed this Consent under seal as of the day and year first above set forth.


                                        GAMMA BIOLOGICALS, INC.



                                        By:      /s/ Edward L. Gallup
                                                 Edward L. Gallup, President


                                        GAMMA BIOLOGICALS INTERNATIONAL, INC.


                                        By:      /s/ Edward L. Gallup
                                                 Edward L. Gallup, President