What I think is most important is using good HOT water when washing
the plates. Hot can be pretty relative. I checked the temperature and it
was about 65 degrees but I think the hotter the better. The rest of the
washing details can help get the plates clean but I think HOT water is
essential.
The other details
Detergent. I spent the last week using the same two sets of plates every
day without using detergent in the washing and there was no significant
difference in the gels. However the plates sometimes looked like dirty
water had dried on the plate despite rinsing with hot water, deionised
water and then distilled water. I don't see that when I use detergent so I
presume the detergent(we use alconox) does help the plates rinse off better.
Rubbing down the plates. When we rinse the plates with hot water we give
them a good rub down with some clean paper towels. This does seem to make
a difference. I used to just wipe down the plates with my gloved hands
while rinsing with hot water. Rubbing down with the paper towels, applying
good pressure does seem to make a difference(especially with the yellow
band problem we were getting)
Dust free. We let the plates air dry in a relatively dust free area. With
all the machines running in the lab and the doors open I'm sure the air
churns up a good bit of dust. We blow the plates off with compressed air
just before pouring the gels and also if we get a bit of blue background on
the plate check.
Periodic maintainace. We soak the plates overnight in multi-terge about
once a month. I don't think it is a "fix all" procedure but it does make
the daily cleaning and pouring gels a bit easier. I have not tried any
acid or base washes partly because I think the daily wash should keep the
plates clean and the acid or base wash should be a last resort and would
still only be a temporary fix
What about the glass? The two sets of plates I am using have been in use
since last November. One set was in storage for a while and I don't know
who the supplier was the other set I bought in November. The plates that
were in storage seem to be consistenly worse for the yellow background,
affecting the bascalling, while the other set never had the problem bad
enough to interfere with the sequence. The history and treatment of these
plates since I started using them is identical(I can think of no difference
in how we used them). So is there any significant difference in the glass
that might bind "problems"? How much variation in glass is there?
Despite the yellow background problem we seem to be doing OK. We don't get
a fade out problem and we can , if we are careful, eliminate any blue
background. I believe we can beat the yellow problem by using th HOT water
and rubbing down with paper towel.
My last comment is to say that I'm sure there are some other "little"
details that are relavant to cleaning the plates. I know that when Mai who
does the DNA sequencing with me washes the plates they usually seem to be
cleaner. Maybe she has a better grasp of that required voodoo element that
Dick referred to?
I hope this is of some help
Martin Pentony
P.A.N. Facility
Stanford University
http://cmgm.Stanford.EDU/pan/