Further optimization of culture method for rat keratinocytes: Titration ofglucose and sodium chloride

The present study further improved the serum-free method of culturing rat k eratinocytes. To obtain the best growth of rat keratinocytes, we modified o ur previous serum-free medium (MCDB153 based medium), particularly the amou nts of glucose and sodium chloride (NaCl). Titration experiments showed the optimal concentration to be 0.8 mM for glucose and 100 mM for NaCl. This m odification eliminated the requirement for albumin, which had been essentia l for colony formation when our previous medium was used. Titration of gluc ose and NaCl, followed by adjustment of essential amino acids and growth fa ctors, produced a new formulation. More satisfactory and better growth was achieved with the new medium than with the previous medium. Accumulation of monoalkyldiacylglycerol (MADAG) was consistently noted in this study; repr esenting the unusual lipid profile. A tendency toward normalization was, ho wever, noted with the neutral lipid profile of keratinocytes cultivated in the new medium: lower production of MADAG was obtained with the new formula tion, rather than the previous one.