title: Measurement of serum prostate specific antigen using IMx prostate specific antigen assay.
abstract: The analytical characteristics of singlet determinations of the IMx prostate specific antigen (PSA)  assay are similar to the mean of duplicates using the Tandem-R not equal to PSA assay. The 2 assays are standardized equally and provide test results that correlate well (r = 0.9997). The IMx PSA assay is more automated, requires less technologist time and provides faster test results. This assay has a minimal detection limit of 0.02 to 0.04 ng./ml. and functional sensitivity at a 20% coefficient of variation of 0.06 to 0.13 ng./ml. With a sensitive lot of IMx PSA reagents, only 38% of post-radical prostatectomy patients had nondetectable values compared to 60% with the Tandem-R PSA assay. The within-person, biological standard deviation of PSA concentrations in post-radical prostatectomy patients was 0.01 ng./ml. Therefore, with a sensitive assay these low concentration measurements should be reliable for monitoring. However, the clinical use of these low concentrations for early detection of tumor recurrence must await further studies.
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota 55905.
authors.forename: G G
authors.initials: GG
authors.lastname: Klee
authors.forename: L A
authors.initials: LA
authors.lastname: Dodge
authors.forename: H
authors.initials: H
authors.lastname: Zincke
authors.forename: J E
authors.initials: JE
authors.lastname: Oesterling
mesh_terms: D000704:Analysis of Variance; D006801:Humans; D016014:Linear Models; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood* / Q000601:surgery*; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity
chemical_list: D011933:Reagent Kits, Diagnostic; D017430:Prostate-Specific Antigen