What if silver stain does not work?

[Bonehammer]

 Hi everybody.
We've having a hard time in our lab trying to understand what's wrong
with our PAGE gels. Sometimes they stain completely and you get
a "chrome-plated" surface with no trace of DNA bands. This happens with
different operators and everyone keeps his/her own stock solutions. The
AgNO3 we have is a little old, and so is the nonbinding silane, but
most of the time we get a good result.

The protocol we use is:
20 minutes in 0,1% w/v CTAB
15 minutes in 0,3% v/v NH3
20 minutes in NH3/silver made as follows:
      0,4 g AgNO3 in 250 ml
      add 1 ml fresh NaOH 1M, then titer (?) with NH3
develop with a solution of 2% w/v Na2CO3 and 600 ul/liter HCHO

Anybody has an idea of what's happening?
Thank you in advance

Chiara Martellossi

--
"No se Pol"
Coffee Genetist from Viva La' e Po' Bon City


Sent via Deja.com http://www.deja.com/
Before you buy.