Zierdt W S, Zierdt C H
Am J Clin Pathol. 1985 Apr;83(4):486-8. doi: 10.1093/ajcp/83.4.486.
An extraction test for stool occult blood was developed using 3,3', 5,5' tetramethylbenzidine (TMB), which gave reliable results in the presence of interfering substances, such as vitamin C, meat fibers, and vegetable enzymes. The new test was applied to 1,320 fecal specimens from hospitalized patients not on dietary restrictions. Of 189 specimens unequivocally positive by slide tests, 48 were negative by the extraction test, 42 were trace reactions, and 99 were 2+ to 4+. Extraction testing was performed on 351 of the 1,082 specimens negative by slide tests. Four of these were from patients taking supplemental vitamin C. Two of these specimens were extraction test positive ( ) and two were extraction test negative. One other specimen, from a patient not on supplemental vitamin C, was extraction test positive. Forty-nine specimens gave equivocal results, with two commercial slide tests for occult blood. By the extraction test, 26 of these were negative, 13 had trace amounts of blood, and 10 were 2+ or 4+.
采用3,3',5,5'-四甲基联苯胺（TMB）开展了一项粪便潜血提取试验，该试验在存在干扰物质（如维生素C、肉类纤维和蔬菜酶）的情况下仍能给出可靠结果。这项新试验应用于1320份来自非饮食受限住院患者的粪便标本。在玻片试验明确呈阳性的189份标本中，48份经提取试验呈阴性，42份为微量反应，99份为2+至4+。对玻片试验呈阴性的1082份标本中的351份进行了提取试验。其中4份来自服用补充维生素C的患者。这些标本中有2份提取试验呈阳性（ ），2份提取试验呈阴性。另一份来自未服用补充维生素C患者的标本提取试验呈阳性。49份标本的结果不明确，采用两种商用潜血玻片试验检测。经提取试验，其中26份呈阴性，13份有微量血液，10份为2+或4+。
