"Red Rain" on ABI377 Gel File

Bruce Roe BROE at aardvark.ucs.uoknor.edu
Mon Jul 1 09:10:41 EST 1996

Chang-pin Huang writes: 
=>     Has anyone seen red lines (or a red smear when it is really bad) which shows
=> up on the ABI377 48cm gel file at the end of the run (at the top of the gel
=> image)?  Do you know why it occurs and how to solve it?  The "red rain" (as we
=> call it) analyzes as a very strong "C" signal and can block out the real
=> sequence. It's not caused by leaking buffer dripping down the plate because the
=> plates are clean and dry after the run.
=> Thank you for reading this message and even more if you have an answer.
=> Chang-pin Huang
	We have observed this "red rain" when gel solutions have not been
properly de-gased.  If you look at the region of the gel plates where the
laser scans, you will notice that small gas bubbles have formed.  We typically
filter the gel solution through a Nalgene filter using a Gast Vacuum Pump and
once filtered, seal the top of the filter with the included plastic cover and
continue to remove any dissolved air by de-gasing for about 10-15 minutes.
This solved the problem of "red rain" for us.  Periodically since implementing
this routinely, someone fails to degas properly and like magic, the "red rain"
appears on these gels.
	Hope this helps.
Bruce A. Roe, Ph.D    Department of Chemistry and Biochemistry
                      University of Oklahoma, Norman, OK 73019-0370, U.S.A.
Phone: (405) 325-4912 or 7610; FAX: (405) 325-7762; e-mail: broe at uoknor.edu
********************** http://dna1.chem.uoknor.edu/ ***********************

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