Fetal calf serum (FCS) is collected from abattoirs in the Southern African region and prepared under conditions which comply with the current agricultural import regulations of the member states of the European Community. South Africa is certified free of Bovine Spongiform Encephalitis (BSE) virus. The biological quality of the serum is to a very large extent determined by the strict adherence to careful procedures at the collection stations. The speed of collection, the cleanliness of the work areas, the temperature, and the quality of supervision in each abattoir are of vital importance.

The Southern African region is isolated by distance from other fetal calf serum producing areas, thus guaranteeing the authenticity of the source. Certification of Origin by the State Veterinary Authorities is obtained as a matter of routine. SA authorities do not allow the import of raw FCS from South America and Europe for reasons of veterinary hygiene.

All sera are processed following GMP procedures. Before pooling, every individual container of raw serum from the abattoir is checked for conductivity (osmolarity), in addition, aliquots from every container are pooled and tested in a spot test for hemoglobin, protein levels and re-growth of 3 cell lines seeded at low cell density. Only if all the above tests pass the QC requirements for raw fetal calf serum, is the material pooled. During the production process, remaining fibrin is removed by a special procedure.

Highveld Biologicals animal sera are routinely gamma irradiated at 28 to 32 kGy (2.8 to 3.2 Megarad) before dispatch; a certificate od irradiation is issued. We have determined conditions and developed a procedure by which serum can be exposed to a high dose of irradiation without losing any biological efficacy. Most viruses and all mycoplasma are destroyed during this process.

A sufficient number of samples are taken at every stage of the sterilization process and tested for sterility on nutrient broth and Sabouraud medium over 10 days. Sera are screened for bacteriophages by plaque assay using E.coli strains. The presence of mycoplasma is determined on hamster kidney cells (Hak) after growth and 3 passages in test serum using a fluorescent monoclonal antibody to common mycoplama species.

Tests for the presence of specific bovine viruses are carried out by standard virological isolation procedures over 3 passages in cell culture.

Determinations of antibodies to BVD, IBR and Ephemeral Fever (P13) and other viruses on request are carried out using standard immunological techniques ELISA and complement fixation.

Six different cell lines are seeded at low cell density (100 cells/2ml) into 24 well plates. Depending on the cell type, after 6-10 days the colonies are stained and counted.

These are carried out using the mouse fibroblast cell line L-929 and the mouse myeloma cell line SP2/0. Five hundred cells per 2ml are seeded into 24 well cell culture plates and counted in duplicate on days 3, 5, 7 and 10.

50 cells of a well adhering cell line (MDBK or other) are planted in 50cm diameter petri dishes; after about 10 days growth the dishes are stained with Giemsa solution and the colonies counted.

A human lymphoblastoid cell line and an attached cell line are used in this test. Cells are diluted to a 5 cells/ml suspension and 200 µl/well planted in 96 well cell culture plates. The single-cell cloning ability is derived after applying the formula for the Poison distribution.

The blood is obtained in registered and controlled abattoirs from healthy adult animals, which are stunned and bled from the jugular vein. The blood is left to clot and the serum separated by centrifugation and then frozen. Because blood from adult bovine usually clots completely, there is no need for repeated freezing and thawing of the serum. The filtration process, irradiation and quality control is the same as described for fetal calf serum.

Because of the presence of large amounts of cryo-precipiting lipoproteins, it is not advisable to freeze and re-freeze sterile horse serum more than once. In order to prevent most cold precipitation, the pH can safely be lowered to pH 6 before filtration, if the serum is used for the preparation of bacterial media.

Blood from other species e.g. sheep, goat, chicken and rabbit are also collected mostly in abattoirs and separated, filtered, gamma irradiated and quality controlled in our own laboratories. The pool size depends on the demand for the product but is usually not less than 10 litre (sheep, goat) or 2 litre respectively (rabbit, chicken).