title: Disagreement between the Roche Cobas Core and Hybritech TANDEM-E PSA assays when measuring free, complexed and total serum prostate specific antigen.
abstract: A comparison of the Roche Cobas Core and Hybritech TANDEM-E PSA (prostate specific antigen) assays revealed a large difference in the reactivity of each assay to the separated free and complexed forms of serum PSA in patients with prostatic carcinoma. The Roche assay was relatively much more responsive to the free form, but the Hybritech assay was relatively more responsive to the complexed form and total serum PSA. It is possible that the adoption of a universal standard for PSA will not completely resolve the disagreement between PSA assay on individual patient samples, and the use of separate assays for the free and complexed forms may be necessary for the further clinical development of PSA as a tumour marker.
authors.affiliation: Department of Chemical Pathology, Royal Marsden Hospital, London, UK.
authors.forename: C R
authors.initials: CR
authors.lastname: Tillyer
authors.forename: M
authors.initials: M
authors.lastname: Konings
authors.forename: P T
authors.initials: PT
authors.lastname: Gobin
authors.forename: J
authors.initials: J
authors.lastname: Iqbal
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood; D002021:Buffers; D005591:Chemical Fractionation; D002850:Chromatography, Gel; D006801:Humans; D007124:Immunoenzyme Techniques; D016014:Linear Models; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis; D012015:Reference Standards; D015203:Reproducibility of Results; D000514:alpha 1-Antichymotrypsin / Q000737:chemistry
chemical_list: D014408:Biomarkers, Tumor; D002021:Buffers; D000514:alpha 1-Antichymotrypsin; D017430:Prostate-Specific Antigen