ChIP - sepharose (May/25/2005 )

hi everyone,

i have a few questions any help is much appreciated:
1/ why are speharose beads blocked with bsa and salmon sperm?
2/ do sepharose beads bind chromatin as well 9i thought they only bind to the antibody fc region)
3/ i have been getting bands in my no antibody as well as non specific antibody samples, this is not a pcr contamination problem.

please help

sepharose beads are preblocked to reduce non-specific binding of protein to your beads, thus only the antibody of interest is captured by the beads.

as for the no antibody control, you should get a band from PCR to confirm the DNA seqeunce you want to IP is in fact there, your IP fraction should have the same band but should be more intense to show that indeed you have enrichment of that fragment by IP.

good luck!

Nick