Development and validation of a quantitative ELISA for the measurement of PSA concentration.
BACKGROUND
Prostate-specific antigen (PSA) has been used for the diagnosis and follow up of prostate cancer (PCa).


METHODS
Mouse monoclonal antibodies (MAbs) were generated against human prostate-specific antigen (PSA) for the development of a sensitive total PSA (t-PSA) assay. Two MAbs, denoted CB-PSA.4 and CB-PSA.9, with affinities of 3.7 x 10(9) and 4.7 x 10(10) l/mol, respectively, were used to develop an enzyme-linked immunosorbent assay (ELISA) for quantifying serum t-PSA concentration.


RESULTS
The detection limit (DL) of the assay was 0.1 microg/l (n=20, mean of "zero" standard+3S.D.), and the recovery of t-PSA was 96-103%. The within-run and between-day coefficients of variation (CV) ranged from 2.1% to 3.2%, and from 2.8% to 6.3% for PSA concentrations of 10 and 1 microg/l, respectively. The equimolar detection of t-PSA and free-PSA was demonstrated by two different methods, one consisted in the comparative evaluation of a sera panel (n=9) with our enzyme-linked immunosorbent assay (ELISA) and four commercial total PSA assays and the concordance with CIS bio total PSA assay. The assay had a linear range of 0.12 to 25 microg/l.


CONCLUSIONS
The analytical performance characteristics of our PSA ELISA suggest that it will provide clinically useful PSA results, particularly when diagnostic algorithms are used.
Acevedo
Boris
B
Recombinant Antibodies Laboratories, Pharmaceutical Division, Center for Genetic Engineering and Biotechnology, Ave 31 and 58, Cubanacán, P.O. Box 6162, 10600, Havana, Cuba. boris.acevedo@cigb.edu.cu
Perera
Yasser
Y
Ruiz
Miriam
M
Rojas
Gertrudis
G
Benítez
Jesús
J
Ayala
Marta
M
Gavilondo
Jorge
J
D000818:Animals; D000911:Antibodies, Monoclonal; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods* / Q000592:standards; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D017430:Prostate-Specific Antigen / Q000097:blood* / Q000276:immunology; D011471:Prostatic Neoplasms / Q000175:diagnosis; D000514:alpha 1-Antichymotrypsin / Q000032:analysis / Q000378:metabolism
D000911:Antibodies, Monoclonal; D000514:alpha 1-Antichymotrypsin; D017430:Prostate-Specific Antigen