In article <Pine.3.89.9407280930.A24016-0100000 at amalgame.MEDENT.UMontreal.CA>, barbeauj at AMALGAME.MEDENT.UMONTREAL.CA (Jean Barbeau) writes: To reduce the clumping try a wash in saline or medium containing DNAase. A lot of times the clumping is due to DNA released from lysed cells. TJ Wickland (tjwickland at aol.com)