Ham's F-12K is Kaighn's modification of Ham's F-12, carrying substantially more amino acids, higher glucose and more sodium bicarbonate to support denser growth. It is specified for a number of ATCC lines including A549. F-12 and F-12K are not interchangeable, so follow whichever your protocol names.
Ham’s F-12K (Kaighn’s modification of Ham’s F-12) is a nutrient-rich medium designed for demanding cell lines and low-serum culture. It builds on Richard Ham’s original F-12 formulation, created for the serum-free clonal growth of Chinese hamster ovary (CHO) cells, and adjusts several components for stronger support. This guide explains what F-12K is, how it relates to F-12, what it contains, and which cells it suits.
Key Facts
- Type: Nutrient-rich medium (Kaighn’s mod of Ham’s F-12)
- Best for: CHO cells and specialized lines
- Notable: Adds putrescine, hypoxanthine, thymidine, zinc
- Buffering: Bicarbonate (use a CO2 incubator)
What is Ham’s F-12K?
Ham’s F-12 is a richly supplemented basal medium first developed by Richard Ham for growing CHO cells with little or no serum. Kaighn’s modification, known as F-12K, raises the concentration of several amino acids and other components, producing a more nutrient-dense medium that supports a broader set of demanding cells. Like other basal media, F-12K supplies salts, amino acids, vitamins, and glucose, and it is completed with serum and glutamine before use.
What is in Ham’s F-12K?
F-12K is notable for its wide range of components, including:
- A broad set of amino acids at raised concentrations compared with standard F-12
- A rich vitamin profile and added trace elements
- Putrescine, hypoxanthine, thymidine, and zinc, components not found in older media
- Glucose and a bicarbonate buffer with phenol red, so it needs a CO2 incubator
What is Ham’s F-12K used for?
F-12K suits cells that benefit from a rich, well-rounded environment, including:
- CHO cells and other lines descended from Ham’s original F-12 work
- Certain endothelial and specialized cell lines
- Cultures moving toward reduced-serum conditions
Ham’s F-12 is also widely blended 1:1 with DMEM to make DMEM/F-12, a popular medium that pairs DMEM’s richness with F-12’s broad component list.
How to supplement and use Ham’s F-12K
Before use, F-12K is completed with serum (commonly 10% FBS) and L-glutamine or a stable glutamine dipeptide. Keep it in a CO2 incubator, store it refrigerated and protected from light, warm it gently before use, and keep the same lot across an experiment for consistency.
Which F-12K do you need?
Browse all F-12K media · all cell culture media
Made in the USA and manufactured in house. Certificate of Analysis with every lot. Bulk pricing, purchase orders and custom formulations welcome.
