FITC extracellular quenching

From: G Robin Barclay (Robin_Barclay@compuserve.com)
Date: Tue Jul 06 1999 - 08:49:35 EST


Dear colleagues
Can anyone recommend a method that works for them for quenching FITC-tagged
agent when bound to the external cell surface but not when the agent is
internalised by the cell.  Trypan blue and crystal violet come to mind -
does anyone have this up and running - can you give method/recipes?  I
assume the quenching agent has to be present in the final cell suspension
to be run on the cytometer - is it just a matter of resuspending the washed
FITC-labelled cells in a quencher solution (in PBS?) and running them
immediately - or are there finite times/temperatures involved.  Is it true
that only Merck trypan blue works?  Has anyone compared trypan blue to
crystal violet - and which came out best?  Are there other quenchers which
may be better?  Do any of these quenchers significantly contaminate the
cytometer tubing - how do you clean after running?
Thanks in advance for any help
Robin Barclay
SNBTS, Edinburgh



This archive was generated by hypermail 2b29 : Wed Apr 03 2002 - 11:53:41 EST