"identification of a substance (especially a protein) by its action as an antigen; \"PSA in the blood can be measured with an immunochemical assay\""@en-us . "0"^^ . "immunoassay"^^ . "105407911"@en-us . . . "0"^^ . . . . . "05740560-n"^^ . "105740560"^^ . . . . "identification of a substance (especially a protein) by its action as an antigen; \"PSA in the blood can be measured with an immunochemical assay\""@en-us . "immunochemical assay"@en-us . "immunoassay"@en-us . .