Identification of human brain from a tissue fragment by detection of neurofilament proteins

Abstract

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.

Potential applications of microRNA profiling to forensic investigations

“…If organ tissue identification was deemed crucial to an investigation, the sample would likely be sent out for cellular/histological analysis to either the Office of the Chief Medical Examiner (OCME) (only in the United States), State Pathologist, or to an external biological analysis company, where immunohistochemical analyses would likely be performed. Other traditional methods, using immunological and enzymatic processes, have previously been suggested as viable tools for this purpose, although none ever gained traction within the forensic science industry (Kimura et al 1995;Takahama 1996;Seo et al 1997;Takata et al 2004). The most confounding limitation of all of the traditional methods is that they require a relatively large sample size that is in nearpristine condition.…”

A New Approach to the Investigation of Sexual Offenses—Cytoskeleton Analysis Reveals the Origin of Cells Found on Forensic Swabs*

“…Within intermediate filaments, four subtypes (vimentin filaments, lamina, neurofilaments, cytokeratins) can be distinguished. In particular, whereas vimentin filaments, lamina, and neurofilaments can be found in muscle, nucleus, and neural tissue (13), respectively, cytokeratins are restricted to the epithelial layers (14). Immunohistochemistry (IHC) is a diagnostic technique routinely used in pathology, and the DAKO Envision+™ detection system (15) makes use of cytokeratins in modern cancer diagnosis (16–19).…”

Forensic transcriptome analysis using massively parallel sequencing

“…The specific challenges with organ tissue samples from crime scenes are limited biological material, putrefaction or damage due to crushing or dehydration. Traditionally, tissues have been identified using immunological or histological methods [61][62][63][64][65]. Recently, assays for tissue identification based on mRNA or miRNA have been developed, based on PCR/CE-methods [66][67][68][69].…”