Seo Y, Kakizaki E, Takahama K
Department of Legal Medicine, Miyazaki Medical College, Japan.
Forensic Sci Int. 1997 Jun 6;87(2):145-54. doi: 10.1016/s0379-0738(97)00049-2.
A sensitive sandwich enzyme immunoassay for identification of brain S-100 protein in blood or bloodstains containing brain tissue is described. A polystyrene ball coated with rabbit anti-S-100 protein IgG was incubated with human S-100 protein, and then with anti-S-100 Fab'-peroxidase conjugate. Peroxidase activity bound to the polystyrene ball was assayed by fluorometry using 3-(4-hydroxyphenyl)propionic acid as the hydrogen donor. The detection limit of human S-100 protein was 0.6 pg (30 amol) per assay tube. The cross-reaction of this sandwich enzyme immunoassay to other organs was approximately 1/100 or less. Antigenic activity of S-100 protein in bloodstains containing brain extracts was detectable after storage for 36 days at room temperature. The ratio of S-100 protein to total protein (ng/mg) in bloodstains when brain tissue was mixed with normal human blood at concentrations of 5-500 mg/ml was approximately 100-fold those of other samples (liver, heart, intestine, and skeletal muscle). These results indicated that bloodstains mixed with brain tissue were clearly distinguishable from others. Thus, in forensic practice, measurement of S-100 protein or the ratio of S-100 protein to total protein is useful to identify blood and bloodstains containing brain tissue.
本文描述了一种灵敏的夹心酶免疫测定法，用于鉴定血液或含有脑组织的血迹中的脑S-100蛋白。将包被有兔抗S-100蛋白IgG的聚苯乙烯球与人S-100蛋白孵育，然后与抗S-100 Fab'-过氧化物酶缀合物孵育。使用3-(4-羟基苯基)丙酸作为氢供体，通过荧光法测定与聚苯乙烯球结合的过氧化物酶活性。每次测定管中人S-100蛋白的检测限为0.6 pg（30 amol）。这种夹心酶免疫测定法对其他器官的交叉反应约为1/100或更低。含有脑提取物的血迹中的S-100蛋白抗原活性在室温下储存36天后仍可检测到。当脑组织与正常人血液以5-500 mg/ml的浓度混合时，血迹中S-100蛋白与总蛋白（ng/mg）的比值约为其他样品（肝脏、心脏、肠道和骨骼肌）的100倍。这些结果表明，与脑组织混合的血迹与其他血迹明显不同。因此，在法医实践中，测量S-100蛋白或S-100蛋白与总蛋白的比值有助于鉴定含有脑组织的血液和血迹。
