General FBS Questions


Does your serum contain tetracycline?

We do not add this antibiotic to serum during manufacturing. Tetracycline is an antibiotic which is often used to treat animals prior to slaughter. Although there should be sufficient time between the last dose of antibiotic and slaughter for the drug to metabolize, this is not always the case and the serum may contain residual amounts of tetracycline.

Gemini tests each lot of fetal bovine serum and Fetalplex™ for tetracycline and we report these results on the product’s respective Certificate of Analysis.


Where does Gemini get its serum?

All GemCell™ products are strictly of US origin. Gemini Bio-Products procures its serum from USDA-approved and inspected slaughter houses, both inside and outside the continental United States. Gemini Bio-Products will supply a Certificate of Origin for any sera product upon request.


How is your serum processed?

Gemini’s animal sera products are collected from USDA-inspected slaughter houses both inside and outside the United States. All GemCell™ products are collected and processed from animals of US origin and must meet Gemini’s stringent quality standards. Gemini’s fetal bovine serum is sterile-filtered through three 0.1µm filters.


What tests are performed on serum?

Gemini Bio-Products tests all serum for endotoxin, hemoglobin, sterility, mycoplasma, virus (species-specific), and growth promotion. We also provide a Biochemical Assay and Electrophoretic Profile with each lot of serum. A Certificate Of Analysis is available for each product lot.

In addition, Gemini runs a standard hormone panel for all 100-500, 100-106 and 100-602 serum lots.