Comparison study of streptavidin-coated microtitration plates

Area of Science:

• Biochemistry
• Immunology
• Assay Development

Background:

• Streptavidin (SAv)-coated microtitration plates are crucial for various immunoassays.
• Variability in plate performance can impact assay reliability and reproducibility.

Purpose of the Study:

• To assess the binding capacity, leaching, well-to-well variation, and immunoassay performance of SAv-coated 96-well plates.
• To determine if high binding capacity correlates with optimal immunoassay performance.

Main Methods:

• Tested commercial and laboratory-prepared SAv-coated plates.
• Quantified binding capacity for europium-labelled biotin and biotinylated antibody.
• Measured SAv leaching under standard immunoassay conditions.
• Assessed well-to-well variation (CV%) for binding capacity.
• Evaluated plate performance in immunofluorometric (TSH) and enzyme immunoassays (CA125, PSA).

Main Results:

• Eu-biotin binding capacity varied widely (4.4 to >150 pmol/well).
• SAv leaching ranged from 0.6-76 ng/well, up to 3.4% of maximal binding capacity.
• Coating-related variation (CV%) ranged from 1.2% to 8.0%.
• High-capacity plates showed increased non-specific binding and variation in immunoassays.
• Some low-capacity plates demonstrated optimal assay performance.

Conclusions:

• Plate binding capacity, homogeneity, and leaching do not directly predict performance in two-site heterogeneous immunoassays.
• Assay-specific evaluation of SAv-coated plates is essential for reliable immunoassay development.
• Plate selection should consider specific assay requirements rather than solely capacity metrics.