RE: ABI's new paper combs
Margaret Robertson (margaret.robertson@hci.utah.edu)
Fri, 21 May 1999 09:46:31 -0600
Skip, we have had the same problem with the first trial batch of ABI paper
combs. The first two we tried were a disaster.
First, the tabs on the comb were too long for the 48cm gels and the comb was
knocked inadvertently way too far into the gel bed!. So cut off the tabs by
at least 1cm before inserting into the gel if you are using 48cm plates!
Second, placement of the comb on the gel bed is really important. If you go
in too deep, as the comb swells it pushes the acrylamide up and out, causing
lane distortions. If you barely touch the gel bed, you risk not making
contact all the way across the 96 lanes as you already experienced.
Third, we found that if you don't remove the comb after the samples have
been run in, you suffer a huge blue haze and lanes that curve all over the
place! That comb is swollen in really tight after 10 minutes, but you can
pull it out if you start at one end and yank hard! We still have a couple
left to try but so far we haven't seen any improvement over the regular
combs if you use a regular 96 comb that fits with resistance as you insert
it into the gel. We regularly change out the 96 combs to make sure we
maintain straight, sharp teeth for good contact. We sometimes get minor
bleed through on the end couple of wells.
Margaret Robertson
Director, DNA Sequencing Facility
University of Utah,
4A 432A, SOM
50 North Medical Drive,
Salt Lake City, UT 84132
Tel: 581-4736
Fax: 585-2978
margaret.robertson@hci.utah.edu
http://www.hci.utah.edu/groups/sequencing