Methods and reagents: Kit wars

Besides the standard ligation and transformation questions that appear
routinely, many ideas resurface when new people join the newsgroup. One
recurring theme is the pros and cons of using prepackaged reagent kits
sold by commercial companies.
 
Kits are designed to be a quick and easy alternative for anything from
mini-prep plasmid DNA extractions to removal of mineral oil from PCR tubes.
There are kits now available for just about every routine procedure used in
molecular biology laboratories.

The battle over kits is ongoing on methds-reagnts.  Mention the use of a kit
and you are bound to start trouble between the `kit' and `no-kit' advocates.
This inevitably spurs `Kit Wars'. Sides are quickly drawn and opinions start
flying, usually falling just short of name calling. Recently, a huge fight
erupted over kits, which prompted me to search for past articles on the topic.
By using Gopher (see TIBS 18, 107-108), I found more than 150 archived
articles posted to bionet.molbio.methds-reagnts related to the use of kits.
Of these, nearly half are devoted to the discussion of `kits' versus `no kits'.

The kit advocates are in search of speed.  They prefer the fastest and safest
route to the end of their experiment.  These researchers are constantly looking
for the best kit to get their experiments to work.  For many, kits are a highly
useful way of completing difficult procedures that would otherwise cost large
amounts of time in trying to locate and collect all the necessary components.
Kits are useful for diagnostic labs that do a large number of routine
procedures in a single day, but they can also be a tremendous help in a one-off
experiment. In addition, use of kits can avoid some fairly dangerous but
necessary steps involved in making your own reagents.

Unfortunately, the attitude of some is `if the kit works, use it'. These people
are thus accused by the `no kit' advocates of being `kit-robots', having little
or no knowledge of the biochemical processes involved in the procedure.
Kit-robots frequently get burned when the kit does not work in their hands, and
generally do not question why it doesn't work, but rather discard it for a
different version.

Although the cost of kits is relatively high, some kit advocates claim that
they can be cheaper than the materials needed to make up all components.  For
example, one netter wrote that both the fmol [TM] DNA sequencing system and
Magic [TM] maxi-prep DNA purification system from Promega are much cheaper than
homemade versions based on the cost of ingredients alone.

The no-kit advocates are those who believe in making almost everything used in
their experiments from scratch.  This has several advantages, including the
fact that the user knows the exact components of the cocktail, their
concentrations and the reasons for including them. It is also more flexible
because the system can be customized to suit a particular need, and any
problems can be investigated.

The major drawbacks of kits include the expense, wasted leftover materials
and proprietary or hidden components.  When companies hide the true components
of their kits under the term `proprietary reagent', many researchers feel it is
their right to know what the components are, and some people who object strongly
to this practice refuse to buy the kit. Perhaps one of the main reasons the
no-kit advocates do not like these mystery components is the lack of
flexibility this bestows on the prescribed method, which requires knowledge of
all the components to make subtle adjustments.  Hidden components are therefore
sometimes seen as an impediment to the advancement of scientific knowledge. For
example, both Promega and Qiagen Inc., as well as many other companies, sell
excellent products for the binding and clean-up of PCR products. However, each
brand of spin column has a proprietary resin for binding DNA, which means that
researchers wanting to use this technique do not have the option of making up
the recipe in their own laboratories.

Perhaps the most outspoken and provocative no-kit person in the newsgroup is
Jim Graham (jgraham@bronze.ucs.indiana.edu), who has spent much of his time
arguing against the use of kits and searching for alternative ways to make his
own reagents. Originally prompted by postings with less exchange of technical
information, he feels compelled to keep himself from succumbing to pre-made
kits because `current advances in molecular biology techniques are no longer
available to the general science public via the literature, but are being sold
to us through commercial companies at inflated prices'.

He pointed out that the MEGAscript [TM] T7 in vitro transcription kit from
Ambion and the AmpliScribe [TM] kit from Epicentre Technologies boast 10-50
times better yields of RNA product from 1 ug of DNA template.  He feels that
competitive researchers have submitted to buying the kits because more variable
yields are obtained with standard transcription conditions described by
Milligan, et al. [1].  In the Ambion catalog, results of an experiment with
T7 RNA polymerase show that the increase is due to a higher concentration of
ribonucleoside triphosphates in the reaction, limiting amounts of which cause
premature termination of RNA synthesis.  It may appear to some that the
companies are doing their own studies in order to hide the components of the
kit, since experiments printed in the catalog are not fully referenced and the
kit components are not always disclosed. However, in this case, details of
similar experiments were found to be published elsewhere [2].

Researchers sometimes feel a sense of loss of control over experimental
procedures by using kits. Care has to be taken to avoid slipping into a quick
and easy way of doing science under the guise of saving time, especially with
the heavy pressures to produce results more quickly than the competitors.
In addition, some professors object to the use of kits by graduate students
because continuous use of kits may lead to the production of a
`follow-by-number' Ph.D. thesis. On the other hand, kits may help produce
papers and graduates rapidly.  An efficient scientist will fall somewhere
in between the kit and no-kit extremes, taking advantage of a kit when
appropriate. Ultimately, the decision to use a kit becomes one of practicality,
with cost weighed against the time and effort needed to make the solutions and
the availability of materials.  Within methds-reagnts, Kit Wars are a no-win
situation.  Everyone has their favorite reason for using or avoiding kits.
There is little doubt that kits will continue to be debated on the newsgroup
for a long time to come.

References:

[1] Milligan, J. F., Groebe, D. R., Witherell, G. W. and Uhlenbeck, O. C.
    (1987) Nucleic Acids Res. 15, 8783-8798

[2] Gurevich, V. V., Pokrovskaya, I. D., Obukhova, T. A. and Zozulya, S. A.
    (1991) Anal. Biochem. 195, 207-213

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particular commercial product or endorse any company. All opinions are
those of the author and do not reflect the opinion of the National Cancer
Institute or the National Institutes of Health.

Copyright: This manuscript is not copyrighted by Elsevier Publishing Company.
However, you may not reproduce any portion for resale or edit the text for
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You found this at the World Wide Web (WWW) Uniform Resource Locator (URL)
ftp://ftp.ncifcrf.gov/pub/methods/TIBS/jan94.txt

Any reference to this column must be cited as the following published article:
Hengen, P. N. 1994. Methods and reagents - Kit wars. Trends in Biochemical
Sciences 19(1):46-47.

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* Paul N. Hengen, Ph.D.                           /--------------------------/*
* National Cancer Institute                       |Internet: pnh@ncifcrf.gov |*
* Laboratory of Mathematical Biology              |   Phone: (301) 846-5581  |*
* Frederick Cancer Research and Development Center|     FAX: (301) 846-5598  |*
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