A High-Capacity Streptavidin-Coated Microtitration Plate

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• 作者：Lasse Vä ; limaa ; Kim Pettersson ; Markus Vehniä ; inen ; Matti Karp ; and Timo Lö ; vgren
• 刊名：Bioconjugate Chemistry
• 出版年：2003
• 出版时间：January 2003
• 年：2003
• 卷：14
• 期：1
• 页码：103 - 111
• 全文大小：138K
• 年卷期：v.14,no.1(January 2003)
• ISSN：1520-4812

文摘

A majority of current immunoassays rely on capturing a specific analyte on a solid phase to allow theseparation of the bound analyte from nonbound components. Streptavidin-coated microtitration platesare widely used for immobilization of capturing antibodies, since they provide a generic surface forimmobilization of any biotinylated molecule and preserve biomolecule activity much better than directpassive adsorption. Our trials to further improve the properties of the plates resulted in a developmentof a modified plate, which has higher binding capacity than currently used control plate. The modifiedcoat was prepared by cross-linking streptavidin chemically prior to adsorption onto the microtitrationwell surfaces. The binding capacities of the plates were measured with biotinylated, europium-labeledmolecules and labeled antigen. The immunoassay performance of the plates was studied withnoncompetitive, sandwich-type assays of prostate specific antigen (PSA) and human chorionicgonadotropin (hCG). The maximum immobilization capacity of the modified plate was up to 2.5 timeshigher than that of the control plate. The higher binding capacity was especially emphasized withsmall-size molecules. The modified high capacity plate increased the linear ranges of the immunoassaysand thus delayed the high-dose hook effect. At high antigen concentrations the signal increased up to59%, and at the conventional linear ranges of the assays, the increase was up to 29%. We concludethat the modified coating method will be valuable for the future miniaturized systems, where highimmobilization capacity is needed at limited areas.