Reply: DN Ligation

Pamela Norton pnorton at
Sat Mar 23 13:33:35 EST 1996

In article <DoMMJr.9q6 at>, pnh at (Paul N
Hengen) wrote:

> : Did you change the lamps of your UV-Transiluminator lately? New and 
> : stronger lamps might damage your DNA while cutting the slices out of 
> : the gel.
> Is it that the lamps change over time, becoming less strong, or is
> it that the newer lamps on the market are stronger? I'm curious
> why replacing the lamp would cause more damage to your DNA?

> Methods FAQ list ->
> Anonymous FTP from as file pub/methods/FAQlist
> TIBS column archive ->

   The former is certainly true. The UV light slowly damages the glass
filter that lies atop the bulbs. This results in less and less UV reaching
the sample over time. I believe that buffers and salts can etch the glass,
and also tend to decrease the transmitted light.

      Pam Norton

P.S. Nice web site, Paul; thanks!

Pamela A. Norton, Ph.D.          Assistant Professor of Medicine
Thomas Jefferson University
Philadelphia, PA 19107           p_norton at

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