NCJ Number
136013
Journal
Journal of Forensic Sciences Volume: 37 Issue: 2 Dated: (March 1992) Pages: 425-431
Date Published
1992
Length
7 pages
Annotation
Heterogeneity and polymorphism of noncarboxymethylated keratins after sodium-dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) has been recently demonstrated; this article reports the correlation in the variation observed in both methods and the usefulness of isoelectric focusing (IEF) followed by silver staining as a method for the analysis of such variation in forensic science cases.
Abstract
Using the same IEF technique, the authors studied the changes in electrophoretic patterns of cosmetically treated hair. Samples of scalp hair from 200 persons and 20 families were analyzed. All donors were questioned about cosmetic manipulation of hair, and, in order to analyze the variation in the keratin patterns, nontreated samples were selected. Additional hair samples of 12 persons were collected so as to study the changes in electrophoretic patterns of cosmetically treated hair. Each donor provided two samples, one before and one after cosmetic treatment. All the samples were washed successively with petroleum ether, ethanol, and water; air dried; and cut into small pieces. The analysis showed that a clear identification of all keratin phenotypes by IEF is possible, even with broad pH ranges. IEF has a number of advantages compared with SDS-PAGE, the most important ones being the high sensitivity, the accuracy for distinguishing some of the patterns, and the concentration effect of IEF which permits phenotyping of old hairs as small as 2 cms. Also, cosmetic treatments can be directly detached by IEF. 4 figures and 21 references