Initiator Integrated Poly(dimethysiloxane)-Based Microarray
as a Tool for Revealing the Relationship between Nonspecific Interactions
and Irreproducibility
- Publication date
- Publisher
Abstract
Nonspecific interactions (NSIs) and
irreproducibility greatly reduce
the accuracy of antigen–antibody screening, which is key to
the discovery of monoclonal antibody drugs and biomarkers identification.
We previously developed a solid supporting material, polymer-coated
initiator integrated poly(dimethysiloxane) (iPDMS), which is able
to provide near-zero background for microarray screening. Here, we
applied two monoclonal antibodies (mAbs), namely, anti-FLAG and HM1,
to screen an iPDMS-based peptide microarray with 2083 peptides from
62 proteins to evaluate NSIs and irreproducibility. In addition to
recognizing their cognate epitopes, the two mAbs also cross-reacted
with random sequences, especially when they were used at high concentrations.
At 50 μg mL<sup>–1</sup>, 295 peptides (14.2% of the
peptide library) had positive reactions to anti-FLAG and only 39 peptides
(1.9%) reacted positively to HM1. Virtually all cross-reactions disappeared
when the [mAbs] reached 0.01 μg mL<sup>–1</sup>. Reproducible
experiments of 404 peptides at various [mAbs] showed that only specific
interactions, molecular mimicry, and mimotope were reproducible between
different experiments. These findings suggest that irreproducibility
was at least partially caused by NSIs. We also demonstrated that repeating
tests and mAb dilution could effectively avoid NSI-related irreproducibility
in serological screening. This will not only largely simplify the
data analysis, but will also make immunoassays more reliable for clinical
research