and bicarbonate ions) and broad-spectrum antibiotics. In certain situations it may be
essential to include a fungicide such as amphotericin B, although this may not always
be necessary. For convenience and ease of monitoring the status of the medium, the
pH indicator phenol red may also be included. This will change from red at pH 7.2–7.4
to yellow or fuchsia as the pH becomes either acidic or alkaline, respectively.
The other key basic ingredient in the cell culture medium is serum, usually bovine
or fetal calf. This is used to provide a buffer for the culture medium, but, more
importantly, enhances cell attachment and provides additional nutrients and
hormone-like growth factors that promote healthy growth of cells. An attempt to
culture cells in the absence of serum does not usually result in successful or healthy
cultures, even though cells can produce growth factors of their own. However, despite
these benefits, the use of serum is increasingly being questioned not least because of
many of the other unknowns that can be introduced, including infectious agents such
as viruses and mycoplasma. The recent resurgence of ‘mad cow disease’ (bovine
spongiform encephalitis) has introduced an additional drawback, posing a particular
risk for the cell culturist, and has increased the need for alternative products. In this
regard, several cell culture reagent manufacturers have now developed serum-free
medium supplemented with various components including albumin, transferrin,
insulin, growth factors and other essential elements required for optimal cell growth.
This is proving very useful, particularly for the pharmaceutical and biotechnology
companies involved in the manufacture of drugs or biological products for human and
animal consumption.Table 2.1Examples of cell lines supplied by commercial sourcesCell line Morphology Species Tissue origin
BAE-1 Endothelial Bovine Aorta
BHK-21 Fibroblast Syrian hamster Kidney
CHO Fibroblast Chinese hamster Ovary
COS-1/7 Fibroblast African green monkey Kidney
HeLa Epithelial Human Cervix
HEK-293 Epithelial Human Kidney
HT-29 Epithelial Human Colon
MRC-5 Fibroblast Human Lung
NCI-H660 Epithelial Human Lung
NIH/3T3 Fibroblast Mouse Embryo
THP-1 Monocytic Human Blood
V-79 Fibroblast Chinese hamster Lung
HEP1 Hepatocytes Human Liver51 2.5 Types of animal cell, characteristics and maintenance in culture