| Popis: |
Methodology for the preparation of cultured fibroblasts for measurement of their free (nonprotein) amino acids was studied in two ways. First, the effect of storage of fibroblasts at −20°C, −70°C, and −196°C was investigated. The recovery of free-cystine declined about 50% after 24 hr of storage and another 25% following six more days of storage at these temperatures. Second, three methods of removing fibroblasts from the surface of tissue culture vessels were studied. The recovery of amino acids was significantly lower when the cells were removed with a silicone rubber scraper than when trypsin or trypsin plus tetrasodium ethylenediaminetetracetate was used. |
