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DETECTION OF Y CHROMOSOMES IN BLOODSTAINS - A REEVALUATION

NCJ Number
57025
Journal
Journal of Forensic Sciences Volume: 24 Issue: 2 Dated: (APRIL 1979) Pages: 366-375
Author(s)
R WIGMORE; D J WERRETT; L A KING; P H WHITEHEAD; A EMES
Date Published
1979
Length
10 pages
Annotation
A METHOD IS DESCRIBED FOR DETECTING Y CHROMOSOMES IN THE LEUKOCYTES OF HUMAN BLOODSTAINS PREPARED ON A VARIETY OF SUBSTRATES. NO DECAY IN Y CELL INDEX WAS SEEN WITH AGE BUT IDENTIFICATION VARIED BY SUBSTRATE.
Abstract
THIS ENGLISH STUDY RAN SERIES OF OPEN AND BLIND TRIALS USING BLOOD STAINS FROM DONORS AND FROM ACTUAL CASE MATERIALS. THE OPEN TRIALS WERE USED TO TEACH OBSERVERS TO IDENTIFY THE Y CHROMOSOME IN SAMPLES PREPARED WITH THE FLUOROCHROME STAIN QUINACRINE MUSTARD. THE 'Y SPOT' IS NORMALLY SEEN AS A BRIGHT CHROMOCENTER IN A QUINACRINE DYE-STAINED NUCLEUS. THE INTENSITY, SHAPE, AND SIZE OF THE SPOT VARY AND THEREFORE THE METHOD IS QUITE SUBJECTIVE, DEPENDING ON THE TRAINING AND ABILITY OF THE OBSERVER. IT WAS FOUND THAT THE OPTIMAL VIEWING CONDITIONS WERE A VERY DARK BACKGROUND IN WHICH THE NUCLEI FLUORESCED A BRIGHT GREEN. THE Y CHROMOSOME WAS SEEN AS A SMALL DISCRETE WHITE FLOURESCENT SPOT ON THE NUCLEUS. IN BOTH THE OPEN AND THE BLIND TRIALS, NO FEMALE HAD A Y CELL INDEX GREATER THAN 10 PERCENT WHILE MALE SCORES RANGES FROM 20 TO 60 PERCENT. IN THE 139 CASES SAMPLES, THE STAIN WAS REPORTED AS MALE IF THE Y CELL INDEX WAS ABOVE 25 PERCENT. FOR THE DONOR TRIALS, A CELL INDEX OF MORE THAN 20 PERCENT WAS USED FOR MALE DONORS WHILE LESS THAN 10 PERCENT PROBABLY INDICATE A FEMALE. TESTS ON VARIOUS SUBSTRATES FOUND THAT COTTON GAVE STATISTICALLY POORER RESULTS THAN BOTH NYLON AND GLASS (SIGNIFICANT AT THE 5 PERCENT LEVEL). STAINS ON LEATHER, COARSE WOOL, AND WOOD WERE DIFFICULT TO ANALYZE. UNLIKE OTHER RESEARCHES, THIS STUDY FOUND THAT THE AGE OF THE STAIN WAS NOT SIGNIFICANT. READINGS WERE OBTAINED IN STAINS UP TO 138 DAYS OLD. THE WELL-ILLUSTRATED DISCUSSION ALSO CONTAINS REFERENCES. (GLR)

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