Behavior of animal blood in blood typing systems. Isoelectric focusing of erythrocyte acid phosphatase and phosphoglucomutase

Isoenzyme band patterns of animal blood erythrocyte acid phosphatase (EAP) and phosphoglucomutase-1 (PGM) were studied by isoelectric focusing on ultrathin polyacrylamide gels. For blood from all animals tested (dog, cat, cow, sheep, and goat), the overall band patterns for both isoenzymes were different from those of the most common human types of these enzymes, although some animal EAP and PGM bands appeared in the human band areas. When mixtures of human and animal red blood cells were studied, it was found that misinterpretation of human types was possible only if the overall band pattern of the mixtures was ignored. For the animal blood tested, the strong PGM bands appearing outside the human band areas could be used as "markers" for the possible presence of animal blood in the samples tested.     

A contribution to the discussion of probabilities and human hair comparisons

The paper by Gaudette and Keeping on "An Attempt at Determining Probabilities in Human Scalp Hair Comparison" in the Journal of Forensic Sciences (Vol. 19, No. 3, July 1974, pp. 599-606) has provoked considerable controversy. This paper highlights two of the sources of the controversy and shows how the probability, 1/4500, quoted by Gaudette and Keeping should be treated with caution. The necessity of the use of a likelihood ratio statistic is described. It is suggested that the hair examination form resulting from the responses to the questionnaire recently distributed by the authors and also the discussions at Quantico (Proceedings of the International Symposium on Forensic Hair Comparisons, 25-27 June 1985, Quantico VA) should be used to facilitate the collection of the data which will be necessary to enable a likelihood ratio statistic to be estimated effectively.