[LOGO]                        Visible Genetics Inc.
- - --------------------------------------------------------------------------------
                              For Immediate Release

Contacts:
Bruno Maruzzo                                       David Sassoon (212) 527-7453
Visible Genetics Inc. (416) 813-3271                Abenaa Hayes (212) 527-8813
                                                    Rowland-Wang Healthcare
Daurio Speranzini, Jr.
Organon Teknika Brazil 55 11 523-8167

     VISIBLE GENETICS INC. AND ORGANON TEKNIKA ENTER EXCLUSIVE DISTRIBUTION
               AND MARKETING AGREEMENT FOR VGI PRODUCTS IN BRAZIL

   - Four Year Agreement Also To Help Speed Commercialization of VGI Products
           and Open Latin American Market to Drug Resistance Testing -

TORONTO, CANADA, April 21, 1999 - Visible Genetics Inc. (VGI, Nasdaq:VGIN) and
Organon Teknika (OT) have entered into an agreement whereby OT will be the
exclusive distributor in Brazil of VGI's OpenGene(TM) automated DNA sequencing
system and GeneKits(TM), including HIV-1, Hep C, Hep B, and TB TruGene(TM)
assays in the diagnostics market. The agreement is for a period of four years
and has provisions that guarantee minimum annual revenues over that period to
VGI.

"This agreement represents an important milestone for VGI and is the second of
many in our worldwide strategy of working with the best healthcare partner in
each geographical market. OT has approximately 100 highly trained, experienced
people in Brazil that will be selling, marketing and supporting VGI products. In
addition, the OT team will help bring VGI's products to early commercialization
by working with VGI to develop a government-based clinical trial program in
Brazil," stated John Stevens, CEO of Visible Genetics. "OT currently markets
NucliSens viral load kits in Brazil and has been very successful with their
clinical trials program," Mr. Stevens continued.


                                       1


"VGI will be an important added value for OT customers in Brazil and this
agreement will truly enhance the products and services we bring to our
customers," said Daurio Speranzini, Jr., General Manager for Organon Teknika,
Brazil and Argentina. "In addition, we believe both companies, together, will
generate a reliable, complete and unique package of products for this market
segment. This local alliance also gives patients the same state-of-the-art
technology that is available in other regions, allowing patients to have better
control and management of their treatment outcomes," he concluded.

Visible Genetics Inc. manufactures and markets high performance automated DNA
sequencing systems and complete diagnostic kits for the analysis of genes linked
to disease. The Company's OpenGene(TM) system employs proprietary stratified DNA
testing and single-tube, single-step sequencing methods to significantly reduce
the time and cost involved in identifying clinically relevant genetic
information. VGI is a leader in the emerging field of pharmacogenomics that uses
genetic information to identify, analyze and treat medical conditions for the
benefit of improving patient care and reducing healthcare costs.

Organon Teknika, a division of Dutch-based Akzo Nobel, has over 25 years
experience in the marketing, sales and support of pharmaceutical and diagnostic
products in Brazil. OT has launched NucliSens, its viral load assay into the
Brazilian market.

                                      ###


                                       2