license for TAQ

Bill Alexander alexanderw at
Fri Apr 19 15:37:54 EST 1996

In Article <JsdI7HA9QfdxEwnW at>, "Dr. Duncan Clark"
<duncan at> wrote:
>In article <alexanderw.1180074138C at>, Bill Alexander
><alexanderw at> writes
>>The PCR patent using thermostable
>>enzymes will lapse in 8 years (or get overturned ;-). 
>Bill you mentioned this before but we cannot get a confirmation that this
>is so. Where did you find this info. ? It is most unusual that Roche
>would waive umpteen years off such an important patent. In Europe it
>appears that the PCR process patent will run for it's full length. The
>PCR license that companies get covers a few patents and runs until the
>last patent expires, currently 16/17 years (whats year here or there!).
I got this right off the front of the Patent.  This will be different for
different countries.  Since this patent is a "continuation-in-part" of an
earlier patent the patentee is prevented (by US law) from extending the life
of the original patent.  This is done using a terminal disclamer which
limits the length to 17 years from the granting of the original parent
patent application.  I don't know how this applies to European patents
except that they are usually for 20 years.  I don't have a copy of any of
the European patents so I don't know when they were filed and when they were
granted.  Can anyone do a search of the European Patents issued to Cetus
(they name the institution as the inventor in Europe).

Inventor: Mullis et al.

Title: Process for amplifying, detecting, and/or cloning nucleic acid
sequences using a thermostable enzyme

Patent Number: 4,965,188

Date of Patent: * Oct. 23, 1990

*Notice: The portion of the term of this patent subsequent to Jul. 28, 2004
has been disclaimed.

What seems to be the original parent application (Ser. No 716,975) was filed
on March 28, 1985 and was later abandoned in favor of a continuation-in-part
which became Patent #4,683,202 (Process for amplifying nucleic acid
sequences) and was issued July 28,1987 with Mullis listed as the sole
inventor.  The original patent aplication may have been split into multiple
"continuation-in-part" applications.   

Of course most everyone thinks this was such an easy step forward from
primer extension but a rejection of a patent application has to be made from
a publication which gives an "enabeling disclosure to one of skill in the
art at the time the invention was made" or render the process "obvious". 

I have not yet read the paper below which is reported to be an earlier
publication of PCR (hope to get it next week).  Does this paper truly teach
how to do an amplification reaction?  Does it use TWO primers in one
reaction and repeatedly denature and reanneal those primers in order to
produce a specific nucleic acid?  If so why didn't someone else pick this up
when primers started to become cheaper in the early '80s?  A methods paper
can also be hard to search for in the literature but a long gap (several
years) between the earlier papers and Mullis's application works in his
favor ("long felt need in the art").

     Kleppe, K., et al   Studies on Polynucleotides: Repair Replication of
short synthetic DNAs as catalyzed by DNA polymerases  J Mol Biol 56:341-361

Bill Alexander
alexanderw at

     "640K ought to be enough for anybody." -- Bill Gates, 1981

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