金黃色葡萄球菌A蛋白(Staphylococal Protein A,SPA)是一種從金黃色葡萄球菌細(xì)胞壁分離的蛋白質(zhì)。能特異性地與人或哺乳動(dòng)物抗體(主要是IgG)的Fc區(qū)域結(jié)合。所以常常使用protein A的柱子來(lái)分離純化單克隆抗體。但是在抗體純化過(guò)程中,protein A能夠從柱子中析出,容易導(dǎo)致抗體的污染,抗體中的protein A會(huì)引發(fā)人體的免疫反應(yīng),所以使用治療的單抗需要嚴(yán)格檢測(cè)其中protein A的含量。Enzo提供的protein A ELISA Kit能夠快速有效檢測(cè)單克隆抗體中protein A的含量。
Protein A標(biāo)準(zhǔn)曲線
A.alphaLISA protein A assay. A 12-point dilution series of the positive control was prepared ranging from 100.000-0.3pg/ml was prepared. 12 background points were used to calculate LDL.
B.Protein A ELISA assay. A 9-point dilution series of the positive control was prepared ranging from 100,000-10pg/ml.
Residual Protein A screen of a panel of human antibodies. A panel of 10 human antibodies was screened for detectible levels of protein A。
煮沸后不同protein A結(jié)構(gòu)的分析識(shí)別。從試劑盒標(biāo)準(zhǔn)曲線中插值得到濃度。通過(guò) 將觀察到的濃度除以預(yù)期濃度計(jì)算出的回收率百分比。 A. Natural Protein A from S. aureus (Millipore), n=9; B. Recombinant Protein A from E. coli (Repligen), n=9; C. Recombinant Cys-Protein A from E. coli (GE), n=12; and D. Recombinant alkaline-resistant Protein A variant from E. coli (MabSelet SuRe from GE), n=12; graphical data represents statistical mean +/- 1 standard deviation。