Thu Aug 20 10:44:00 EST 1992
In article <1992Aug19.171937.10562 at magnus.acs.ohio-state.edu>, rrumpf at magnus.acs.ohio-state.edu (Robert Rumpf) writes...
>Any netheads out there have any experience with the InVitroGen Dipsticks used
>for determining DNA quantity in solutions? I have heard the literature claims
>of being as easy to use as litmus paper, sensitive enough to detect 20ng/ul
>with only a 1ul sample, etc. What I would like are personal
>experiences/opinions, etc on whether this stuff works, is cost-effective,
A colleague has tried the Dipstick, and says that it works. However, it
requires some processing of the stick before quantitation. Also, though the
ad does not state it, the kit instructions note that it detects not only
DNA, but RNA as well. If working with Ethidium Bromide holds no fear for
you, you might try a fluorescence spot test we often use. Briefly, 2 ul
droplet of the DNA whose concentration is spotted on saran wrap layed on a
UV transilluminator. An 8 ul droplet of a .5 ug/ml solution of EtBr is mixed
by pipetting up-and-down. A series of droplets containing known quantities
of DNA are also spotted. The fluorescence of the test sample is then compared
to the knowns. Like the Dipstick, the best response is obtained with amounts
as low as 1 ng an as high as 10 ng. A picture can taken with the appropriate
filter for a permanent record (and also to avoid having to stare at a UV box).
When quantitating, be sure to include a zero ng control, since the EtBr itself
can fluoresce. Also, ignore the fluorescence seen at the edges of the sample.
Once the solutions of EtBr and the known samples are prepared, this method
takes only a few minutes to do.
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