The Importance of Serum Bottles for Serum Quality
Serum is the gelatinous fluid obtained after removing fibrinogen from plasma, including various types such as fetal bovine serum (FBS), calf serum, adult bovine serum, and horse serum.
Serum is the gelatinous fluid obtained after removing fibrinogen from plasma, including various types such as fetal bovine serum (FBS), calf serum, adult bovine serum, and horse serum. Serum is typically stored in specialized serum bottles, placed in appropriate storage conditions according to its type. Several factors influence serum quality, including:
Endotoxins
The domestic standard requires endotoxin levels to be no higher than 5 EU/mL. Endotoxins are components of bacterial cell walls released after bacterial lysis. High endotoxin levels indicate improper sterile handling during blood collection and production. If endotoxin levels are excessively high, the serum is likely contaminated.
Total Protein Content
The typical range for fetal bovine serum is 30–40 mg/mL. If the value is too high, it suggests that the blood was collected from older cattle rather than fetal calves. If the value is too low, it may indicate dilution or adulteration of the serum.
Hemoglobin Content
The standard for hemoglobin is no higher than 20 mg/dL. The redder the serum, the higher the hemoglobin content, which may indicate excessive hemolysis during blood collection and processing.
pH Level
Domestic serum typically has a pH above 7.5, while imported fetal bovine serum usually has a pH below 7.5. The exact reason is unclear but may be related to the age of the cattle. This can serve as an indicator to distinguish the origin of the serum.
Microbial Contamination
Serum can be contaminated with bacteria, fungi, mycoplasma, bacteriophages, and various pathogenic viruses. While E. coli has minimal impact on serum quality, pathogenic viruses—particularly bovine viral diarrhea virus (BVDV)—are present in over 90% of domestic serum samples. Microbial contamination is one of the key factors affecting the quality of domestically produced serum.
While these biological factors significantly impact serum quality, the quality of serum bottles also plays a crucial role. If the bottle has poor sealing or inadequate sterilization, it can lead to serum contamination. Contaminated serum used in cell culture experiments may slow cell growth or even halt it completely, compromising experimental results.
Therefore, when selecting serum, it is essential to evaluate both the serum quality and the integrity of the serum bottle’s seal to ensure optimal performance and reliability.