Washing Cell Clusters

[Dan B.]

Greetings,

Can anyone suggest a method to wash relatively fragile cell 
clusters (to remove Paraformaldehyde and replace with PBS) 
without centrifugation?  I don't want to disturb the morphology
before microscopy and photographing.  These are round clusters 
of about 200-300 cells held together by somewhat weak adhesion 
proteins.  Thanks much!

- Dan (dburgess at bcm.tmc.edu)