Fetal Bovine Serum (FBS) is a commonly used supplement in cell culture media, providing a rich source of growth factors, hormones, and nutrients vital for supporting cell growth and proliferation in scientific research. Its complex composition makes it invaluable for various applications, including vaccine production and fundamental biological studies. The proper handling and storage of FBS are crucial to maintain its quality and ensure consistent results in laboratory settings.
Optimal Refrigerated Storage
Fetal Bovine Serum can be stored at refrigerated temperatures, typically between 2°C and 8°C, for a limited duration. Most manufacturers recommend using refrigerated FBS within two to eight weeks. This short-term storage allows for convenient access for immediate laboratory use without the need for repeated thawing from frozen stock.
Storing FBS at 4°C helps to slow down the degradation of its sensitive components, such as proteins and growth factors, compared to room temperature. However, prolonged storage beyond the recommended period at this temperature can lead to a decrease in its growth-promoting capabilities and an increased risk of protein aggregation or precipitation.
Alternative Storage Conditions
For long-term preservation, Fetal Bovine Serum should be stored frozen at -20°C or colder, such as -70°C or -80°C. At these temperatures, FBS can remain stable for up to five years from the date of manufacture. Freezing significantly minimizes the degradation of its active components, ensuring its efficacy over extended periods.
Room temperature storage is generally unsuitable for FBS, except for very brief periods, typically a few hours to a day. Exposure to warmer temperatures rapidly accelerates the degradation of heat-sensitive components and significantly increases the risk of microbial contamination, which can compromise its performance and experimental outcomes. For this reason, thawed serum should be used promptly or aliquoted and refrozen.
Maintaining FBS Quality
Maintaining the quality of Fetal Bovine Serum involves careful handling practices, particularly during thawing and aliquoting. Gradual thawing is recommended, typically by transferring frozen FBS to a 4°C refrigerator overnight. Rapid thawing methods, such as using a hot water bath or microwave, can compromise the serum’s quality by denaturing proteins and causing precipitation. After thawing, gently mix the serum by inverting the bottle to ensure homogeneity and prevent foaming.
Aliquoting FBS into smaller, single-use volumes immediately upon receipt and thawing helps to minimize repeated freeze-thaw cycles. Each freeze-thaw cycle can lead to the degradation of proteins and growth factors, diminishing the serum’s overall quality and potentially affecting experimental reproducibility. Aseptic technique is crucial during aliquoting to prevent microbial contamination, which can rapidly spoil the serum and impact cell culture health. Signs of degradation or contamination include increased turbidity, unusual color changes, or the presence of visible precipitates that do not readily disperse.