Fetal Bovine Serum (FBS) is a sterile, light brown colored liquid separated from the blood of the bovine fetus. All material meets with the approval of the U.S. Department of Agriculture and is obtained from sources free of BSE, Foot and Mouth Disease and other reportable diseases pertaining to the species.

Serum is derived from whole clotted blood, aseptically collected via cardiac puncture according to industry standards, and processed in a facility that is compliant with FDA guidelines for Class I Medical Devices. Serum is separated from the collected blood by refrigerated centrifugation, true pooled, and frozen immediately. Only raw serum that meets strict specifications for endotoxins, residual hemoglobin concentration, pH, and microbiological quality is approved for production. The raw pooled serum is filtered through a triple series of 0.1 µm sterilizing grade filters. The serum is dispensed in a Class 100 facility following cGMP guidelines. Products are filled in square media bottles. These bottles are gamma irradiated to achieve the highest level of sterility assurance (10^-6 SAL), and tested for heavy metals, physio-chemical, cytotoxicity, and bacterial endotoxin as per U.S. Pharmacopeia.

A representative number of serum samples from each production lot are analyzed using the following criteria:

• pH: The pH is measured to verify compliance with the product specification. All equipment is calibrated using standards which are traceable to the National Institute of Standards and Technology.
• Osmolality: The osmolality of each serum lot is measured to verify compliance with the product specification. All equipment is calibrated using standards which are traceable to the National Institute of Standards and Technology.
• Sterility Testing: The sterility of the final product is tested to confirm the absence of bacterial and fungal contaminants for representative samples of each lot using the direct inoculation method in accordance with USP current edition.
• Hemoglobin Testing: To verify that proper collection and processing procedures have been followed, a quantitative and colorimetric assay is performed to determine the residual hemoglobin concentration in each product lot.
• Mycoplasma/Ureaplasma: Each final product lot is tested for the absence of mycoplasma. Our test is accurate within the detection limits of the method referenced.
• Viral Testing: Each lot of serum is tested for adventitious viruses using cell culture techniques, using modified procedures adapted from the Code of Federal Regulations, Title 9, Part 113.53, "Requirements for Ingredients of Animal Origin."
• Endotoxin Test (LAL): Each lot is tested for bacterial endotoxin.
• Total Protein: To verify animal age and compliance with the product specifications, the total serum proteins are measured.
• Serum Identity/Integrity: Each lot of serum is certified for identity and integrity.
• Heat Inactivation: Heat inactivated sera have been heated at 56°C for 30 minutes.
• Growth Promotion and/or Plating Efficiency: Each lot of serum is tested for its ability to support in vitro growth of specific cell lines.
• Biochemical Profile: Each serum lot may be analyzed for the following parameters:Total Bilirubin, Potassium, Total Protein, Calcium, SGOT, Albumin, Cholesterol, SGPT, Creatinine, Sodium, Glucose, LDH, Phosphorus, Urea, Globulins (Alpha, Beta, Gamma).

Heat Inactivation of Serum

Serum is a very complex supplement containing mostly proteins but also growth factors, hormones, amino acids, sugars, trypsin inhibitors, and lipids. The most common types of sera include fetal bovine (FBS), newborn calf (NCS), horse (equine), pig (porcine), and human. FBS has been adopted as the standard supplement because of its rich content of growth factors and its low gamma globulin content.

Because serum is a blood product, it contains complement which can lead to complement-mediated cell lysis. Heat inactivation of serum is performed to inactivate complement. Immunological studies and the culture of insect cells warrant the need for heat inactiviation of the serum.

During the inactivation, the temperature and duration should not exceed 56.3°C and 30 minutes, respectively. Overheating or periods of heat longer than 30 minutes may compromise the integrity of growth factors, amino acids, and vitamins in the serum. Heat inactivation may also cause the proteins and lipids concentrated at the bottom to gel; constant swirling during the heat inactivation process will prevent the appearance of these white globules. Serum compromised by improper heat inactivation may adversely affect the growth of cells in culture.