Removing unincorporated nucleotides from probes

[kim at m44.unm.edu]

Hello group:

Does anyone really know why we run probes through a spin column to remove
unincorporated nucleotides?  Do they really cause nonspecific background on a
blot, or do they just make the first few washes really hot?  The May 1992
BioTechniques has an article in which a blot is probed without prehybridization
and without cleaning up the probe, and it came out beautifully.  The only
difference in their technique was that the blot was sandwiched between two
pieces of filter paper (3MM paper, I assume).  I was just wondering if probe
clean-up was necessary at all.

Daniel Kim