Multi-center analytical performance evaluation of the Access Hybritech® p2PSA immunoassay.


Total PSA assays measure both complexed and non-complexed forms of PSA while free PSA assays only measure non-complexed forms. Free PSA is a mixture of isoforms including immature PSA (proPSA) with retained portions of the leader sequence (e.g. [-7], [-4], and [-2]proPSA) and nicked forms (BPSA). ProPSA isoforms in male sera have been associated with prostate cancer. This study characterized the analytical performance of a chemiluminescent immunoassay for [-2]proPSA.

The Access Hybritech p2PSA assay is a sandwich immunoassay using an anti-[-2]proPSA monoclonal antibody attached to paramagnetic beads and an anti-PSA monoclonal antibody conjugated to alkaline phosphatase calibrated with recombinant [-2]proPSA. Analytical studies including sensitivity (CLSI EP17-A) and imprecision (CLSI EP5-A2) were performed.

The Access Hybritech p2PSA assay for [-2]proPSA had a dynamic range of 0.5 to 5000 pg/ml. The total CV of the assay was <7% for [-2]proPSA concentrations between 20 and 1000 pg/ml. The LOB was 0.50 pg/ml, LOD 0.69 pg/ml, and LOQ 3.23 pg/ml (20% CV). There was no hook effect up to 15,000 pg/ml. There was a <5% difference between calibrator and reagent lots and no interference from normal serum constituents.

The Access Hybritech p2PSA assay is a robust immunoassay for the measurement of serum [-2]proPSA.


One biomarker makes reference to this publication:

  • Arockiasamy DA
  • Broyles DL
  • Carlson CM
  • Chan DW
  • Klee GG
  • Mizrahi IA
  • Pierson TB
  • Roberts WL
  • Sokoll LJ
  • Tam JE
  • van Schaik RH
PubMed ID
Appears In
Clin Chim Acta, 2012, 413 (15-16)