Thu Nov 18 11:46:43 EST 1993

I recently tried the InVitroGen DNA dip stick, and found it to work poorly.
While it is very sensitive, my specific complaints are: it is time consuming.
It takes about 15 minutes to get a reading, and it requires frequent attention
(ie you can't really do much else in that time.) The system is not set up to
process multiple samples at one time. While my first sample was developing, I
began a second (with new wash buffer). However, I reused the developer and 
fixative solutions. This one came out with a high background (a pale blue haze
on the membrane). Apparently these guys want us to use fresh solutions and for
every dip stick. If you have a lot of samples to quantitate - forget it! Also,
the dip sticks themselves were quite hard to work with. The instructions say
to keep the stick vertically aligned against one side of the cuvette. This was
very frustrating, as the stick is subject to gravity as well as electrostatic
interactions. Also, my samples didn't really match any of their printed stds.,
meaning I had to repeat the whole procedure anyways. For routine estimation
of fairly concentrated samples I will stick to the spec (Which can also 
estimate purity, which the dip stick can't do), and use EtBr staining on a gel
for more dilute samples.
Brett Lindenbach
Washington University - St. Louis
brett at borcim.wustl.edu

More information about the Methods mailing list