Paul N Hengen pnh at
Wed Dec 15 18:35:01 EST 1993

In article <9312110024.AA07064 at biology.UCSC.EDU>
 niflab at (Ludwig Lab-UCSC) writes:

| In response to the query raised about my earlier post I was thinking along 
| lines mentioned by Jim ie just because you are using CsCl and can't see 
| RNA does not mean that there isn't any!
| Regarding internal controls, the most reliable I think would be lambda DNA 
| similar ie something isolated from phage particles. 

> I don't agree.  WOn't a linear lambda band at a different density than a 
> closed circular plasmid?

I think the control referred to here is very clean DNA used for estimation of
DNA concentration by absorbance spectroscopy, and not the position of the band
in a CsCl/EtBr ultracentrifuge tube. To answer your question, linear DNA will
band separately from the cccDNA using this method.

* Paul N. Hengen, Ph.D.                           /--------------------------/*
* National Cancer Institute                       |Internet: pnh at |*
* Laboratory of Mathematical Biology              |   Phone: (301) 846-5581  |*
* Frederick Cancer Research and Development Center|     FAX: (301) 846-5598  |*
* Frederick, Maryland 21702-1201 USA              /--------------------------/*

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