Protective effects of amino acids against freeze-thaw damage in mammalian cells.

Amino acids were tested for their effectiveness as cryoprotectants. From the results of this study, the mean fractional area loss of amino acid residues upon incorporation in globular proteins, a measure of hydrophobicity, is generally inversely proportional to the freeze-thaw protection by these free amino acids. However, the pattern of protection ("fingerprint") of cells by various amino acids is different from that of the enzymes liver alcohol dehydrogenase and calcium ATPase of the sarcoplasmic reticulum. Furthermore, unlike the case with these enzymes, for cells glutamine is the best cryoprotective agent of the amino acids tested.