ARID1A is a subunit of the mammalian SWI/SNF complex, which is thought to regulate
gene expression through restructuring chromatin structures. Its gene ARID1A is frequently mutated
and ARID1A levels are lowered in several human cancers, especially gynecologic ones. A functional
ARID1A loss may have prognostic or predictive value in terms of therapeutic strategies but has not
been proposed based on a quantitative method. Hardly any literature is available on ARID1A levels in
tumor samples. We developed an indirect enzyme-linked immunosorbent assay (ELISA) for ARID1A
based on the current EMA and FDA criteria. We demonstrated that our ELISA provides the objective,
accurate, and precise quantification of ARID1A concentrations in recombinant protein solutions, cell
culture standards, and tissue lysates of tumors. A standard curve analysis yielded a ‘goodness of
fit’ of R2 = 0.99. Standards measured on several plates and days achieved an inter-assay accuracy of
90.26% and an inter-assay precision with a coefficient of variation of 4.53%. When tumor lysates were
prepared and measured multiple times, our method had an inter-assay precision with a coefficient of
variation of 11.78%. We believe that our suggested method ensures a high reproducibility and can
be used for a high sample throughput to determine the ARID1A concentration in different tumor
entities. The application of our ELISA on various tumor and control tissues will allow us to explore
whether quantitative ARID1A measurements in tumor samples are of predictive value