FRTL Cell Growth Medium


Content: 500 milliliter
Product number: 820601
Product information "FRTL Cell Growth Medium"

FRTL Cell Growth medium is based on Ham’s F12K medium and supplemented with hormones, L-Glutamine and FBS. Together with the TSH stock solution coming with the medium, it is ideally suited for propagating FRTL and FRTL-5 cells. Directly before usage, add the respective amount of TSH. Each aliquot provides enough TSH for preparing 100 ml complete FRTL Cell Growth Medium with a final TSH concentration of 16.5 ng/ml.

Cell lines cultured using FRTL Cell Growth Medium

Phase contrast images of FRTL-5 cells: FRTL-5 cells growing in FRTL Cell Growth Medium without TSH (right) and supplemented with 16.5 ng/mL TSH (left) 8 days after seeding.

Medium preparation

  1. The FRTL Growth Medium is a basic medium, which must be finalized by adding the supplement mix provided in frozen 15 mL tubes.
  2. It is recommended to prepare 100 mL of medium. Take out 90 mL basic medium and add 10 mL of supplements from one of the 5 tubes, defrosted at 37°C for a maximum of 5-10 minutes. Although the supplement mix is a sterile solution, we recommend filtering it through a sterile 0.2 µm pore PES membrane syringe filter. The volume of 100 mL is sufficient to start culturing the cells and for the first subculture steps.
  3. Adding 10 mL supplement mix to 90 mL basic medium will result in a TSH final concentration of 16.5 ng/mL.

The proliferation of FRTL-5 cells depends on the presence of TSH in the cell culture medium

TSH-dependent FRTL-5 cell numbers. FRTL-5 were seeded at the same cell density in a medium without TSH (blue bars), containing increasing TSH concentrations (orange bars), and harvested after 8 days of incubation at 37°C/5% CO2. Cells were counted using the DeNovix Celldrop electronic cell counter in the presence of Trypan Blue.


  • Basic Medium: Keep refrigerated at +2°C to +8°C in the dark. Freezing and warming up to +37° C minimize the quality of the product. Do not heat the medium to more than 37°C or use uncontrollable sources of heat (e.g., microwave appliances).
  • Supplements: Keep frozen at -20°C in the dark.

Quality control

  • pH = 7.2 +/- 0.02 at 20-25°C.
  • Each lot has been tested for sterility and the absence of mycoplasma and bacteria.

Contamination-free cells
To identify mycoplasma contaminations we perform PCR-based and luminescence-based mycoplasma assays. We further determine any bacterial or fungal contamination through our standardized manufacturing processes.
Bulk order
Besides genomic DNA, RNA, cell pellets, and cell lysates in bulk, we can offer large quantities of assay-ready cells, plated cells in multiple formats, and frozen or growing cells. Contact us to receive a quote.
Authenticated cells
Each manufactured batch of cell lines* is authenticated via STR analysis. Contact us if you require a publication-ready STR report for your cells (*human, hamster, mouse, rat, and dog cells).
HLA alleles
HLA characterization is available from more than 200 cell lines. HLA class I -A, B, C, and Class II HLA-DPA1, -DPB1, -DQA1, DQB1, and DRB1 alleles were obtained by next-generation sequencing methodologies (NGS) for class I and class II alleles.