FISH background

Mario Nenno [Biologie] nenno at
Sun Jan 31 15:00:10 EST 1993

Mike Morris (mike at wrote on bionet.molbio.methds-reagnts
25 Jan 1993 with Subject: FISH background:
  >    We are doing fluorescent in situ hbridization on human chromosomes: 
  > single copy, painting, interphase, the lot. 
  >    Although we have no trouble (at last!) getting good signals and good
  > specificty, we very often have a significant "halo" of cytoplasm around
  > metaphases, which fluoresces slightly (with biotin-labelling, avidin
  > development). I suspect that this may be due to cellular biotin picking
  > up the label.
  >         Anybody have any suggestions - what is causing the background?
  >                                        how can I get rid of it?
Hallo Mike and other FISHers,

first you have to know I'm doing FISH on plant chromosomes.
But we have the same observation of '"halo" of cytoplasm'. To my
experience a pretreatment with the protease pepsin can reduce this halo.
To my interpretation it is due to the proteolysis of proteins in the
cytoplasma and in the end it causes the removal from the slide.
In the right concentration and incubation time there is no danger to
chromosomes (own observations). 

More information about the Methods mailing list