Permanent sickle cell preparations.

The globulin content of the standard solution in the vials is standardized either by a Kjeldahl or a biuret determination. When available Lederle (gamma) globulin diluted 1:200 can be used for this purpose as well. The diluted Lederle standard globulin coagulates on heating and so cannot be used as a sterilized standard. An interesting phenomenon was observed while preparing the sterilized water-diluted serum. The total protein value determined in the diluted serum before and after sterilization remains constant, but the globulin value determined before and after sterilization showed a marked increase by this denaturation procedure. After renewed concentration as used for the electrophoresis of C.S.F. this solution showed only one globulin fraction and no albumin at all.