FAQ general

In almost every instance, the serum is NOT contaminated. Occasionally thawed serum will appear cloudy. It is usually the result of normal serum components. Fibrin (a non-globular protein involved in the clotting of blood) is most common. Fibrin appears in small quantities as a fine flake or may occur as a lump of a semi-solid […]

The price of different sources varies for several reasons. There is a perception that countries like the U.S., Australia, and New Zealand have stricter controls on meat processing than second and third world countries, creating a greater demand and commanding higher prices. An additional misconception is that Australia and New Zealand are safer sources because […]

“U.S. Origin” serum is collected in facilities located within the contiguous United States of America undergoing continuous inspection by the United States Department of Agriculture (USDA). “USDA Origin” serum is collected from facilities located outside the U.S. which are approved for the import of ruminant meat products and byproducts. Current eligible countries that may export […]

Hemoglobin in finished fetal bovine serum results from the lyses of red blood cells during the transportation and processing of blood into serum. When collection techniques were not as good, hemoglobin concentration was used as an indicator of the quality. There are no reported effects on cell cultures from hemoglobin concentrations of less than 100 […]

Endotoxin is a complex lipopolysaccharide (LPS) found in gram-negative bacteria’s outer cell membrane and is typically waterborne. Bacteria shed endotoxin in large amounts upon cell death and when they are actively growing and dividing. Endotoxin is measured in Endotoxin Units per milliliter (E.U./mL). One EU/mL equals approximately 0.1 to 0.2 ng/mL. Endotoxin is directly related […]

Mycoplasma species are often found in research laboratories as contaminants in cell culture. Mycoplasmal cell culture contamination occurs from individuals or contaminated ingredients in the cell culture medium. The name was chosen because Mycoplasmas were observed to have a fungi-like structure (“Myco”) and because it also had a flowing plasma-like design without a cell wall […]

The serum producing process includes allowing the blood to clot, then removing the serum by centrifugation.  Fibrinogen is a large fibrous glycoprotein found in blood which functions in hemostasis and injury healing, and is essential to forming clots.  Fibrinogen is insoluble; the conversion to fibrin occurs during clotting.  Not all of the fibrinogen is converted […]