Gauldie J, Tang H K, Corsini A, Walker W H
Clin Chem. 1980 Jan;26(1):37-40.
We compared use of protein-A-containing Staphylococcus aureus bacteria with conventional ammonium sulfate precipitation and second-antibody methods of separating bound and free antigen in the radioimmunoassay of a hapten (digoxin) and protein (ferritin) in human sera. In each case, values obtained with the heat-killed, formalin-fixed bacteria correlated well with those found by established methods. No matrix effects were detected in either hapten or protein measurements. Because of the affinity of S. aureus for rabbit IgG, rabbit antisera could be used with a small number of bacteria to detect antigen in the presence of 50-fold excess human IgG. The availability of S. aureus and ease of handling make this reagent a rapid, economical alternative of general applicability in radioimmunoassay.
我们比较了含蛋白A的金黄色葡萄球菌与传统硫酸铵沉淀法以及第二抗体法在人血清中半抗原（地高辛）和蛋白质（铁蛋白）放射免疫分析中分离结合抗原和游离抗原的应用。在每种情况下，用热灭活、福尔马林固定的细菌获得的值与既定方法得到的值相关性良好。在半抗原或蛋白质测量中均未检测到基质效应。由于金黄色葡萄球菌对兔IgG具有亲和力，因此在存在50倍过量人IgG的情况下，可使用少量细菌与兔抗血清来检测抗原。金黄色葡萄球菌的可得性及其易于操作的特点使其成为放射免疫分析中一种快速、经济且具有普遍适用性的替代试剂。
