BECAUSE OF THE IMPORTANCE OF HAIR IN FORENSIC MEDICINE, IT IS HELPFUL TO DEAL DIRECTLY WITH GENE PRODUCTS IN IDENTIFYING HAIR. WHEN ONE CAN DEAL WITH PRIMARY GENE PRODUCTS MORE SPECIFICITY IS POSSIBLE THAN WHEN ONE DEALS WITH MULTIPLE GENE PRODUCTS, (I.E., THE SHAPE OF AN INDIVIDUAL FEATURE). EXAMPLES OF USE OF PRIMARY GENE PRODUCTS SUCH AS STRUCTURAL PROTEINS OR ENZYMES ARE TISSUE TYPE AND BLOOD TYPE ANALYSIS FOR SUSPECT IDENTIFICATION PURPOSES. HAIR ANALYSIS IS THEREFORE SIMILAR TO BLOOD TYPE AND TISSUE TYPE ANALYSIS. ALTHOUGH THERE ARE IMPORTANT DIFFERENCES BETWEEN ETHNIC AND RACIAL GROUPS, SIMILARITIES CAN BE OBSERVED BETWEEN INDIVIDUALS. FURTHERMORE, CONSIDERABLE HETEROGENEITY EXISTS WITH RESPECT TO MOST MORPHOLOGICAL FEATURES OF HAIR IN A SINGLE INDIVIDUAL. THE PURPOSE OF THIS STUDY WAS TO DEVELOP TECHNIQUES TO CHARACTERIZE THE POLYPEPTIDES OF HAIR PROTEINS AND TO USE THESE IN IDENTIFICATION OF SPECIFIC HAIR SAMPLES OF NORMAL INDIVIDUALS. THE HAIR WAS SOLUBILIZED IN ALKALINE BUFFERS CONTAINING 6 M UREA AND A REDUCING AGENT. FOLLOWING ALKYLATION OF THE PROTEINS TO THE S-CARBOXYMETHYL DERIVATIVE, POLYACRYLAMIDE DISC ELECTROPHORESIS WAS PERFORMED. ELECTROPHORESIS IN A 7.5 PERCENT ACRYLAMIDE GEL SHOWED A VARIANT PATTERN OF THE ALPHA POLYPEPTIDES IN ABOUT 5 PERCENT OF CAUCASIAN SAMPLES AND IN 1 PERCENT TO 2 PERCENT OF BLACK SAMPLES. USING 17.5 PERCENT ACRYLAMIDE GELS., SEVERAL VARIANT PATTERNS WERE FOUND IN THE MATRIX PROTEINS, THE PRINCIPAL ONE OCCURRING WITH A FREQUENCY OF ABOUT 5 PERCENT. VARIANT POLYPEPTIDES CAN BE USED AS HIGHLY SPECIFIC GENETIC MARKERS WHICH ARE NOT ALTERED BY ENVIRONMENTAL FACTORS. FIGURES AND A BIBLIOGRAPHY ARE PROVIDED IN THE STUDY. (AUTHOR ABSTRACT MODIFIED--LWM).