Ham's F-12K (Kaighn's) Medium is a modification of Ham's F-12 Nutrient Mixture. Ham's F-12K (Kaighn's) Medium was developed for primary human hepatocytes, as well as for some rat and chicken liver cells in a reduced serum environment.Ham's F-12K (Kaighn's) Medium contains many components not found in traditional basal media, such as putrescine, thymidine, hypoxanthine, zinc, and higher levels of all amino acids and sodium pyruvate.