Identification of human brain from a tissue fragment by detection of neurofilament proteins.
We developed a method for identifying human brain from a tissue-like fragment by detection of neurofilament protein (NF) using enzyme-linked immunosorbent assay (ELISA). NF was extracted from 0.1 g of organ/tissue homogenized with Tris-HCl buffer (pH 7.2) containing urea, phenylmethylsulfonyl fluoride (PMSF), EDTA and, EGTA. It was necessary to dilute the extract at more than 2(3)-fold to avoid immunosuppression by urea. Positive reaction was always obtained for NF-H in 2(3)-fold diluted extract of brain tissue, however, NF-L and NF-M were not always detected when a brain fragment contained gray matter. Human cerebral white matter could be easily distinguished from other organs/tissues by detecting any of the NF-subunits. Brains of human and some animals could be discriminated by detecting NF-L or NF-M, although the species specificity of NF-H was not good. Our findings suggested that detection of NF-H was more useful than NF-L and NF-M for identifying a brain from a tissue-like fragment. The present ELISA method for NF-H could identify human brain specimens under the following conditions: putrefied at 4 degrees C for up to 3 weeks, dried at 37 degrees C for at least 4 months, heated at 50 degrees C for at least 4 weeks. Our results showed that our method is useful for identification of brain tissue in forensic stain analysis. Two practical cases are described.
Takata
Tomoyo
T
Department of Legal Medicine, Okayama University Graduate School of Medicine and Dentistry, Shikata-cho 2-5-1, 700-8558, Japan.
Miyaishi
Satoru
S
Kitao
Takashi
T
Ishizu
Hideo
H
D000328:Adult; D000818:Animals; D001921:Brain / Q000473:pathology*; D001923:Brain Chemistry; D002415:Cats; D002417:Cattle; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005554:Forensic Medicine / Q000379:methods*; D006168:Guinea Pigs; D006801:Humans; D008297:Male; D051379:Mice; D008875:Middle Aged; D016900:Neurofilament Proteins / Q000032:analysis*; D011817:Rabbits; D051381:Rats; D012680:Sensitivity and Specificity; D012756:Sheep; D013045:Species Specificity; D013048:Specimen Handling; D013552:Swine
D016900:Neurofilament Proteins