“…After 3 days, monolayers were ®xed with 100 % methanol for 5 min, stained with haematoxylin for 3 min followed by immersion in running tap water for several minutes until cell nuclei appeared blue. Assuming that each cell contained only one nucleus a cell count was conducted using image analysis software (Aequitas IDA, Dynamic Data Links, Cambridge, U.K.) linked via a video camera to a Nikon Diaphot microscope as previously described (Tebbs et al, 2000). Monolayers were counted at 20 Â magni®cation.…”