Various Rat-1-derived cell lines were transferred into medium containing 0.05% fetal calf serum either with or without 2μM β -oestradiol and observed after 48h.

Cells were transferred to Liebovitz L-15 media with 10% fetal calf serum in a heated (37 C) open-air chamber 15 minutes prior to imaging.

Cells were collected into tubes containing 100 μl fetal calf serum, centrifuged, and resuspended in 1% formaldehyde.

They were then washed by centrifugation (300 g for 10 minutes) and resuspended in the same buffer and fetal calf serum.

Therefore, we chose to add the drug directly into the culture medium containing 5% fetal calf serum.

The two colon lines were grown in RPMI medium (Gibco) with 10% fetal calf serum.

Sympathetic neurons were treated with 2.5% fetal calf serum immediately prior to transfection.

The cells, derived from mouse embryos, that were grown in a medium containing calf serum died out whereas those raised in a serum-free preparation did not.

Cells were grown over night in RPMI containing 20% fetal calf serum.

Many researchers have tried to obtain a medium for growing antibodies that is free from calf serum.