Enzo Biochem Awarded Patent Covering Method to Correct Certain Gene Abnormalities
   Technology Would Permit "Editing" of DNA in a Cell
   FARMINGDALE, N.Y.--(BUSINESS WIRE)--March 15, 2000-- Enzo Biochem, Inc. (NYSE:ENZ - news)
   announced today that it has received a patent from the U.S. Patent and Trademark Office that covers
   nucleic acid compositions and methods for editing and correcting certain abnormalities in genes.

   ``Given the vast body of knowledge available through charting the human genome, the ability to correct
   inherent errors in the genes of a subject, and certain other medically important genetic material where
   alterations may be indicated, becomes very relevant,'' said Dean L. Engelhardt, Ph.D. Senior Vice
   President of Enzo. ``The procedure outlined in the patent could provide the means for these corrections.''

   U.S. Patent No. 5,958,681 claims a method and materials suitable for correcting point mutations or small
   insertions or deletions of genetic material. For example, genetic abnormalities caused by single
   nucleotide alterations or small deletions could be corrected through the insertion or exchange of the
   correct or desired sequences into the genome of the cell where the error exists.

   Enzo said that this new technology provides the Company with an additional therapeutic platform and
   another unique approach for treating genetic-based diseases, as well as other applications. Enzo also
   said that this gene editing technique differs from other gene therapies that usually require the insertion of
   an entire new gene to correct a nonfunctional or incorrectly functional gene.

   This invention could lead to creation of a normally functioning gene by correcting a mutated or altered
   gene sequence. It could correct, for example, an inborn error of metabolism for a condition such as
   hemophilia. Potentially, it could also be used to correct a mutated p53 gene that controls cell growth. In
   the mutated gene, the cell growth is uncontrolled, resulting in cancer. In the corrected p53 gene, the cell
   growth would be restored to its normal, non-cancerous state.

   These genetic alterations could be used to inactivate oncogenes, genes in a cancer cell that function to
   maintain the cancerous state of the cell, or to inactivate genes in a virus essential for continued growth of
   the virus. Such genetic alterations could also have application in genetic diseases such as Tay-Sachs
   and sickle cell anemia.

   In addition to its application in human therapeutics, this new technology could find (I substituted d for e in
   fine>>>HEY LOOK GUYS and GALS, IT WORKS!!!!!) use in veterinary and agricultural applications.

   Enzo said that it has begun discussions leading to possible further application of this technology towards
   specific therapeutic products.

   ``The fundamentals of the methods and materials covered in the patent have been recognized by
   researchers, and the `681 patent provides Enzo with a commanding position to pursue what appears to be
   a highly promising new genetic correcting mechanism,'' said Dr. Engelhardt. ``This technology represents
   another novel approach for treating genetic defects and viral diseases utilizing Enzo's pioneering science
   focused on modifying the genetic makeup of an organism.''

   The method and materials covered by the '681 patent work by correcting the specific gene within cells
   with defined short gene sequences. These sequences are held in place through formation of a triple helix
   complex. The principle of the invention is that when the short gene sequence containing the correct
   sequence is held in close proximity to the target DNA to be corrected, the probability of a double
   crossover or an editing event becomes quite high. This involves triplex-forming DNA sequences that bind
   to specific regions in the DNA in a sequence-specific manner to provoke DNA repair. The triple helix holds
   the sequences in close proximity and at a precise point in the gene long enough for recombination,
   exchange or insertion to take place with a high frequency.

   >>>END<<<

   ENZO has harnassed a recombinant trick (mechanism) of the recombinant virus, to INTEGRATE a repair,
   rather than alter the human genome, as a retro-virus can successfully initiate. Very ingenious!

   Looks like a very strong Patent. Note the gene seeking attribute. If a specific "FIX" is targeted to a
   sequence just long enough to match only one in the human genome, the insertion, utilizing perhaps a
   lentiviral vector, which carries ONLY this payload, would repair ONLY THOSE CELLS with the need for
   the repair.

   So you take HIV, strip out its payload for manufacturing more HIV, replace instead the specific construct
   in question and deliberately infect the Patient. Sounds bad? Well, once HIV has no payload it cannot pull
   one from thin air. It ceases to be HIV and instead becomes HRV (Human Repair Virus). Now that would
   be wonderful! And given ENZO's track record with stealth techniques, I expect a package with no
   measurable presence, save the fix!

   Could it be that this Patent is so well conceived and timed, that the infringers of old NEED IT BADLY? So
   ENZO gets to set its terms, which include a reasonable BACK PAYMENT, to pony up and share this
   wonder? Could be?

   Sincerely,

   Larry Glaser

   P.S. Trioxynucleic Acid is born...