DNA ppt and CoCl2

[Helge Weissig]

Hi netters,

i have a problem w/ ppt a 20 bases long oligonucleotide after incubation in
a Cobaltchloride containing buffer. To be more precise: the oligo comes
down quite nicely, but so does enough CoCl2 to screw up my next experiment
even after extensive (2x) washing w/ 70% EtOH (i.e. i get a brown ppt of
Co-something, possibly due to the DTT in my next buffer - this is my next
question).

------> how can i get rid of the CoCl2? (gel purification should work but i
am as always in a hurry)

------> what is that brown crap i get?

any hints from someone who did'nt sleep through her/his anorganic chemistry
classes?


helge

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