A high-capacity streptavidin-coated microtitration plate.

Area of Science:

• Biochemistry
• Immunotechnology
• Materials Science

Background:

• Immunoassays commonly use solid-phase capture for analyte separation.
• Streptavidin-coated plates are standard for immobilizing biotinylated molecules, preserving activity better than direct adsorption.

Purpose of the Study:

• To develop a modified microtitration plate with higher binding capacity.
• To evaluate the immunoassay performance of the modified plate.

Main Methods:

• Chemically cross-linking streptavidin before adsorption onto microtitration well surfaces.
• Measuring binding capacities using biotinylated, europium-labeled molecules and labeled antigen.
• Assessing immunoassay performance with prostate specific antigen (PSA) and human chorionic gonadotropin (hCG) sandwich assays.

Main Results:

• The modified plate demonstrated up to 2.5 times higher maximum immobilization capacity compared to control plates.
• Enhanced binding capacity was particularly notable for small-sized molecules.
• Modified plates improved immunoassay linear ranges and delayed the high-dose hook effect, with signal increases up to 59% at high antigen concentrations.

Conclusions:

• The novel streptavidin coating method significantly enhances immobilization capacity.
• This high-capacity plate improves immunoassay performance, extending linear ranges and mitigating hook effects.
• The modified coating is advantageous for miniaturized diagnostic systems requiring high immobilization capacity in limited areas.