Sialic acid and cell aggregation.

Chick embryo neural retina cells from 7-, 10and 14-day embryos and muscle cells from 9-day embryos, dissociated mechanically or with trypsin, reaggregate at the same initial rate whether treated before and during aggregation with active or inactive iV-acetyl neuraminidase. 7V-acetyl neuraminidase treatment also has no effect on the size or number of aggregates formed over 24 or 48 h of aggregation. It was also found that the amount of trypsin used to dissociate the tissue into single cells alters the initial rate of aggregation but has no effect on the size or number of aggregates formed over a 24-h period.