ISOELECTRIC FOCUSING WAS APPLIED TO THE STUDY OF HUMAN HAIR ROOTS. HAIRS WERE PULLED RAPIDLY IN A RANDOM MANNER FROM VARIOUS REGIONS OF THE SCALPS OF EIGHT INDIVIDUALS WHO HAD BEEN BLOOD TYPED BY ISOLECTRIC FOCUSING AND WHOSE PGM PHENOTYPES WERE ESTABLISHED. PUBIC AND CHEST HAIRS WERE ALSO TAKEN FROM CERTAIN DONORS, AND THESE HAIRS WERE USED IMMEDIATELY AFTER PULLING. SOME HAIRS WERE REMOVED FROM THE SCALPS OF SOME DONORS BY FIRM BUT SLOW PULLING. THIS PROCEDURE CAUSED ANAGEN HAIRS TO BE OBTAINED THAT WERE FREE OF SHEATH CELLS. ENZYME VISUALIZATION WAS PERFORMED USING AN AGAR OVERLAY METHOD WITH A REACTION MIXTURE. RESULTS OBTAINED FROM THE ROOTS OF HEAD, PUBIC, AND CHEST HAIRS WERE SIMILAR TO THOSE OBTAINED FOR BLOOD FOLLOWING ISOELECTRIC FOCUSING AND PGM VISUALIZATION. IN EACH CASE, THE PGM PHENOTYPE FROM HAIR MATCHED THAT OBTAINED FROM BLOOD. THE INCREASED DISCRIMINATING POWER OF THE ISOELECTRIC FOCUSING TECHNIQUE, COMPARED TO THE STARCH GEL TECHNIQUE, PROVIDES A MORE SENSITIVE MEANS OF TYPING HAIR. THE USE OF PGM ACTIVITY IN HAIR ROOT SHEATH CELLS AND THE APPLICATION OF ENZYME TYPING TO HAIR ROOTS ARE DISCUSSED IN TERMS OF THEIR VALUE IN CASES OF ASSAULT, INCLUDING MURDER AND RAPE, WHERE HAIR IS SNATCHED OR PULLED FROM SCALPS OF PARTIES INVOLVED. ILLUSTRATIONS OF ISOELECTRIC FOCUSING PATTERNS ARE INCLUDED. (DEP)