Because Clontech's Tet-On and Tet-Off Systems are extremely sensitive, even “antibiotic-free” fetal bovine serum that has no negative effect on cell growth may still exhibit enough activity to alter Tet-regulated gene expression. You can be confident that Tet System Approved FBS will not adversely affect Tet-On or Tet-Off experiments.
*Testing for the presence of tetracyclines in fetal or calf serum is not equivalent to the highly sensitive functional testing that is performed on Clontech Tet System Approved FBS.
Two Versions of Tet System Approved Fetal Bovine Serum Are Available
- US-Sourced FBS: A premium cell culture serum that is collected in the United States.
- Tet System Approved FBS: An economical alternative obtained from non-US, USDA-approved sources.
All sera are subjected to the same rigorous testing to ensure full inducibility.