We had the same problem here, and in a comparison of Fiquoll-Hypaque,
Lymphoprep and "home made" percoll gradient (1.080) the home made gradient
worked best (lowest clumping and highest yield of PBMC). You can also try
adding 10%FCS to the diluting/washing PBS. We also experienced the donor
differences you described.
Good luck!
**************************************************
Katja Adolf, PhD student
Aarhus University Hospital
Allergy and Lung Research Clinic, Denmark
email: kad at biobase.dk
**************************************************
Carol Iversen <rczci at unix.ccc.nottingham.ac.uk> wrote in message
news:Pine.SOL.4.05.9902121021020.5801-100000 at granby...
>I am isolating human PBMC using 'Lymphoprep'. Some times it works but
>nearly 50% of separations result in PBMC clumping together and either
>sinking to sit on the RBC or forming a 'membrane' at the interface of the
>ficoll/buffer. I have tried using PBS and RPMI, I have heard a citrate
>buffer may prevent this - does anyone have a recipe? Or any other advice
>or explaination why this happens?
>Thanks
>
