Alternatives for harvesting cells grown on microcarriers: effects on subsequent attachment and growth.

In order to facilitate the subpassaging of cells in microcarrier cultures for scaling up culture volumes, alternative procedures for harvesting cells from microcarriers were investigated. A variety of enzymes including trypsin and dextranase were tested separately and in combination to evaluate cell viability after detachment, recovery, and subsequent attachment and growth of cells following inoculation of the cells in the next microcarrier culture. Treatment of confluent microcarriers with dextranase detached cells efficiently and with high viability and in addition totally digested the dextran-based matrix of Cytodex, thus avoiding the possible need to separate the harvested cells from the microcarriers. Dextranase alone resulted in cells harvested as sheets, but if used in combination with trypsin, a single cell suspension of harvested cells was obtained.