Re: Cord blood

Barry Grimes (bagrim1@pop.uky.edu)
Thu, 31 Jul 1997 21:11:36 -0400

William,,
C' can be a bit of a pain sometimes - activity must be titered and it's
quite labile.It's also more expensive than NH4Cl lysis - but perhaps less
membrane altering. I'm wondering more about the cytotoxicity of the GlyA. I
would think one would need an IgG - those tend to be good C' fixers. If
this could work it might provide a nice way to look at WBCs without
subjecting them to the rigors of a shocking solution. It would also perhaps
help rid CD34+ stem cell preps of scatter similar erythroblasts.

>Hi Flow people
>I'm working on cord blood phenotyping, interested in rare leukocyte subsets.
>As those who work on these preps will know, there is a problem with RBC and
>erythroid contamination, variable but up to 80% of ficoll separated PBMC.
>They don't seem to lyse easily using hypotonic methods, and as some are
>nucleated, I wouldn't expect this to be an ideal approach.
>Gating on FS/SS can partly improve percentage of CD45+ cells but not much.
>We really want to clean the preps up, and I have been thinking of using
>complement lysis of the RBC, perhaps with an antibody to Glycophorin A.
>There are antibodies of different isotypes available, including IgM, I
>presume this might be the best to start with for complement lysis. I
>believe GlyA has a complement regulatory function, I don't know if this
>will be a problem.
>
>Does anybody have any hints on this, either the lysis method, or is there a
>simpler way of removing the erythroid cells that I have missed out on?
>Immunomagnetic separations can get a bit expensive, and positive selection
>of CD45+ cells will cause problems with further analysis. I presume there
>must be a lot of people doing this sort of thing, because of the CD34
>interest.
>
>Thanks.
>
>______________________________________________
>Dr William Smith
>
>Institute for Child Health Research
>(Company Limited by Guarantee ACN 009 278 755)
>Subiaco, Western Australia, 6008
>PO Box 855 West Perth WA 6872
>
>Ph 61 8 9340 8792/8388, Fax 61 8 9388 3414
>email williams@ichr.uwa.edu.au
>______________________________________________

Barry Grimes
Manager, Hematopoiesis FACS Laboratory
UKMC Hematopoiesis Center
800 Rose St.
Lexington,KY 40536-0093
606-323-8193
bagrim1@pop.uky.edu