Stability of free prostate-specific antigen in serum samples under a variety of sample collection and sample storage conditions

Urology ◽  
1996 ◽  
Vol 48 (6) ◽  
pp. 33-39 ◽  
Author(s):  
David Woodrum ◽  
Chet French ◽  
L. Blair Shamel
Keyword(s):  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Storage Conditions ◽  
Sample Storage ◽  
Sample Collection ◽  
Serum Samples

Measurement of total and free prostate specific antigen (PSA) in human serum samples using an ultra-microanalytical system

2021 ◽  
pp. 114470
Author(s):  
Juliette M. Cazanave Mora ◽  
Ruben del Valle García ◽  
Lilian Pérez López ◽  
Dunia C. Bequer Ariza ◽  
Orlando Zulueta Rodríguez ◽  
...  
Keyword(s):  
Human Serum ◽  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Serum Samples ◽  
Human Serum Samples

Verification of Harmonization of Serum Total and Free Prostate-Specific Antigen (PSA) Measurements and Implications for Medical Decisions

2020 ◽  
Author(s):  
Simona Ferraro ◽  
Marco Bussetti ◽  
Sara Rizzardi ◽  
Federica Braga ◽  
Mauro Panteghini
Keyword(s):  
Prostate Specific Antigen ◽  
Information Needs ◽  
Specific Antigen ◽  
International Standards ◽  
Serum Samples ◽  
Medical Decisions ◽  
Measuring Systems ◽  
Performance Specifications ◽  
Current Measuring ◽  
Roche Cobas

Abstract Background Previous studies have shown that the harmonization of prostate-specific antigen (PSA) assays remained limited even after the introduction of WHO International Standards. This information needs updating for current measuring systems (MS) and reevaluation according to established analytical performance specifications (APS) and the characteristics of antibodies used. Methods Total (tPSA) and free (fPSA) PSA were measured in 135 and 137 native serum samples, respectively, by Abbott Alinity i, Beckman Access Dxl, Roche Cobas e801, and Siemens Atellica IM MSs. Passing–Bablok regression and difference plots were used to compare results from each MS to the all-method median values. Agreement among methods was evaluated against APS for bias derived from biological variation of the 2 measurands. Results The median interassay CV for tPSA MSs (11.5%; 25–75th percentiles, 9.2–13.4) fulfilled the minimum APS goal for intermethod bias (15.9%), while the interassay CV for fPSA did not [20.4% (25–75th percentiles, 18.4–22.7) vs goal 17.6%]. Considering the all-method median value of each sample as reference, all tPSA MSs exhibited a mean percentage bias within the minimum goal. On the other hand, Alinity (+21.3%) and Access (−24.2%) were out of the minimum bias goal for fPSA, the disagreement explained only in minimal part by the heterogeneity of employed antibodies. Conclusions The harmonization among tPSA MSs is acceptable only when minimum APS are applied and necessitates further improvement. The marked disagreement among fPSA MSs questions the use of fPSA as a second-level test for biopsy referral.

scholarly journals Comparison of Four Commercial Kits for Isolation of Urinary Cell-Free DNA and Sample Storage Conditions

Diagnostics ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 234 ◽  
Author(s):  
Eun Young Lee ◽  
Eun-Ju Lee ◽  
Hana Yoon ◽  
Dong Hyeon Lee ◽  
Kwang Hyun Kim
Keyword(s):  
Cost Efficiency ◽  
High Sensitivity ◽  
Storage Conditions ◽  
Sample Storage ◽  
Sample Collection ◽  
Cell Free Dna ◽  
Free Dna ◽  
Zymo Research ◽  
Free Circulating Dna ◽  
Commercial Kits

Urinary cell-free DNA (cfDNA) is an attractive body fluid for liquid biopsy. In this study, we compared the efficiencies of four commercial kits for urinary cell-free DNA (cfDNA) isolation and of various sample storage conditions. Urinary cfDNA was isolated from 10 healthy individuals using four commercial kits: QIAamp Circulating Nucleic Acid Kit (QC; Qiagen), MagMAX™ Cell-Free DNA Isolation Kit (MM; Applied Biosystems), Urine Cell-Free Circulating DNA Purification Midi Kit (NU; Norgen Biotek), and Quick-DNA™ Urine Kit (ZQ; Zymo Research). To assess the isolation efficiency, an Agilent 2100 Bioanalyzer with High Sensitivity DNA chips was used, and cfDNA yield was defined as the amount of cfDNA obtained from 1 mL of urine. MM and QC provided the highest cfDNA yield in the 50–300 bp range, and MM and NU gave the highest cfDNA yield in the 50–100 bp range. In particular, the NU kit was efficient for isolation of more fragmented cfDNA in the range of 50–100 bp with the lowest cellular genomic DNA contamination. ZQ had the best cost-efficiency for isolating the same amount of urinary cfDNA. Samples stored at −70 °C with the addition of 10 mM EDTA resulted in the highest cfDNA yield 3 months after sample collection.

scholarly journals The Influence of Serum Sample Storage Conditions on Selected Laboratory Parameters Related to Oxidative Stress: A Preliminary Study

Diagnostics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 51
Author(s):  
Lilla Pawlik-Sobecka ◽  
Katarzyna Sołkiewicz ◽  
Izabela Kokot ◽  
Aleksandra Kiraga ◽  
Sylwia Płaczkowska ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Serum Sample ◽  
Storage Conditions ◽  
Wilcoxon Test ◽  
Reference Ranges ◽  
Sample Storage ◽  
Serum Samples ◽  
The Stability ◽  
The Individual ◽  
The Impact

The present work aims at accessing the stability of biological material stored for diagnostic and scientific purposes. The influence of the temperature, storage time, and cyclic thawing on concentration stability of selected oxidative stress parameters in human serum was investigated. The study group consisted of 20 serum samples collected from healthy volunteers aged 18–52. The parameters whose reference ranges were not determined and to which validated determination methods did not correspond were examined by manual methods (FRAP and AOPP). Automatic methods were used to determine routine laboratory tests (albumin, total protein, bilirubin, uric acid) using the Konelab 20i® analyzer. The samples were stored at various temperatures (room temperature, 4 °C, −20 °C, −80 °C) for max 6 months and were subjected to cyclic thawing at 1 month intervals. In order to check whether any differences between the concentrations of the studied parameters existed when the samples were stored in various conditions, the paired Student t-test or Wilcoxon test and comparison to desirable bias were applied. Based on the obtained results, it was found that the temperature and time of serum sample storage significantly affected the stability of the analyzed parameters and determined different shelf lives of serum samples for oxidative stress examination. Therefore, continuing the investigation concerning the impact of storage conditions on various serum parameters seems justified due to the discrepancy between the individual results obtained by different researchers and the inconsistencies between the results of scientific research and the applicable recommendations.

scholarly journals Miniature Single-Particle Immunoassay for Prostate-specific Antigen in Serum Using Recombinant Fab Fragments

2000 ◽  
Vol 46 (11) ◽  
pp. 1755-1761 ◽  
Author(s):  
Harri Härmä ◽  
Piia Tarkkinen ◽  
Tero Soukka ◽  
Timo Lövgren
Keyword(s):  
Prostate Specific Antigen ◽  
Single Particle ◽  
Binding Capacity ◽  
Specific Antigen ◽  
Genetically Engineered ◽  
Covalent Attachment ◽  
Serum Samples ◽  
Fab Fragment ◽  
Fab Fragments ◽  
Total Psa

Abstract Background: Quantitative, miniaturized nucleic acid assays and immunoassays can be developed with single microparticles, microfluorometric detection, and intrinsically fluorescent lanthanide chelates in a multiple assay format to decrease reagent consumption, cost, and assay time. We used recombinant Fab fragments to capture and detect free and total prostate-specific antigen (PSA) from serum in a submicroliter volume single-particle immunoassay. Methods: Genetically engineered thiol-Fab or thiolated monoclonal antibodies (mAbs) were covalently attached onto uniformly sized 60-μm maleimide-activated microparticles. Free and total PSA were detected with europium- or terbium-labeled Fab fragments on a single microparticle using a microfluorometer in a time-resolved mode. Results: The detection limit of the free- and total-PSA assays (mean + 3 SD of zero calibrator) was 0.35 μg/L, with a total volume of 330 nL per particle. An excellent correlation was found in microparticle and microtiter-well assays for 21 serum samples: slopes for free and total PSA were 1.06 ± 0.03 and 1.03 ± 0.02, respectively (Sy|x = 0.084 and 0.057 μg/L), with intercepts of 0.013 ± 0.018 and 0.013 ± 0.017 μg/L (R >0.99). Furthermore, the particle-immobilized Fab fragment had a PSA binding capacity 1.5-fold higher than the intact mAb capacity on a single microparticle. Capacity, kinetics, and sensitivity of the Fab fragment and intact mAb assays in the microparticle and microtiter well formats are discussed. Conclusions: With site-specific (cysteine tail) covalent attachment of Fab fragments on a microparticle, subattomole amounts of PSA can be detected quantitatively.

scholarly journals Measurement of Prostate-specific Antigen by Use of a Novel Blood Collection and Analytical System

2002 ◽  
Vol 48 (8) ◽  
pp. 1272-1278 ◽  
Author(s):  
Barbara R Grzeda ◽  
Tuan Le Bui ◽  
Cheryl N Warner ◽  
Tracy L Pirucki ◽  
Lisa M Dewey ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostate Specific Antigen ◽  
Whole Blood ◽  
Prostate Cancer Screening ◽  
Specific Antigen ◽  
Blood Collection ◽  
Serum Samples ◽  
Stabilizing Solution ◽  
Professional Assistance ◽  
Comparison Of The Results

Abstract Background: Prostate-specific antigen (PSA) is widely used in the detection and monitoring of prostate cancer. We developed a system for the self-collection and transport of capillary whole blood for PSA analysis, with the goal of reducing phlebotomy visits and, thus, increasing the access and utilization of PSA in prostate cancer screening and monitoring. Methods: The blood collection device [BIOSAFE Blood Transport System (BTSTM)] collects 70 μL of blood through a heparin-coated material into 200 μL of stabilizing solution. The diluted whole blood is used for measurement of PSA by a modified version of the Hybritech® Tandem-MP PSA Assay. Results were compared for matched samples of professionally and self-collected BTS blood and for matched BTS samples sera from blood collected by venipuncture. Imprecision for the whole-blood PSA measurement was estimated from analysis of whole-blood controls in duplicate, twice per day, over 20 days. Results: BTS samples (n = 140) collected by a qualified healthcare professional compared with serum samples yielded the regression equation: y =1.02x + 0.04 (Sy|x = 0.35; r = 0.99). Comparison of the results for samples (n = 128) collected by the patient without professional assistance with serum samples yielded: y = 1.08x + 0.02 (Sy|x = 0.31; r = 0.99). The between-run CVs at 0.069, 0.53, 2.9, and 10.7 μg/L were 21%, 6.0%, 3.5%, and 3.8%, respectively. PSA was stable in BTS samples stored for 21 days at 18–24 °C and for 7 days at 37 °C. Conclusion: The BIOSAFE BTS system allows accurate and convenient measurement of circulating PSA by a precise method for diluted whole blood.

scholarly journals Preanalytical Determinants of Total and Free Prostate-Specific Antigen and Their Ratio: Blood Collection and Storage Conditions

1998 ◽  
Vol 44 (3) ◽  
pp. 685-688 ◽  
Author(s):  
Klaus Jung ◽  
Philipp von Klinggräff ◽  
Brigitte Brux ◽  
Pranav Sinha ◽  
Dietmar Schnorr ◽  
...  
Keyword(s):  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Storage Conditions ◽  
Blood Collection ◽  
And Storage

scholarly journals Reference Reagents for Prostate-specific Antigen (PSA): Establishment of the First International Standards for Free PSA and PSA (90:10)

2000 ◽  
Vol 46 (9) ◽  
pp. 1310-1317 ◽  
Author(s):  
Brian Rafferty ◽  
Peter Rigsby ◽  
Matthew Rose ◽  
Thomas Stamey ◽  
Rose Gaines Das
Keyword(s):  
Confidence Interval ◽  
Prostate Specific Antigen ◽  
Recombinant Dna ◽  
Collaborative Study ◽  
Specific Antigen ◽  
International Standards ◽  
Serum Samples ◽  
International Standard ◽  
Free Psa ◽  
Total Psa

Abstract Background: Prostate-specific antigen (PSA) measurements in serum by immunoassay are widely used in the screening, diagnosis, and monitoring of patients with prostate cancer although the lack of common reference reagents has led in the past to wide differences in estimates. We report here the results of a WHO international collaborative study in which two preparations of PSA representative of the main immunoreactive components in serum, free PSA and PSA 90:10, and a preparation of recombinant DNA-derived PSA were assessed as potential standards for the calibration of diagnostic immunoassays for PSA. Methods: Coded vials of the candidate materials and serum preparations containing PSA in the clinically important range were provided to the 10 laboratories in the study, and participants were asked to perform PSA assays currently in use in their laboratories. Data from 89 immunoassays by 26 different method-laboratory combinations were contributed to the study and analyzed centrally at the National Institute for Biological Standards and Control. Results: Potency estimates of the preparations relative to the in-house calibrators were in good agreement with the target value of 1 μg of total PSA/vial, the preparation of free PSA giving 1.10 μg/vial (95% confidence interval, 0.99–1.21 μg/vial) and PSA 90:10, 1.11 μg/vial (95% confidence interval, 1.04–1.18 μg/vial). No immunoreactivity was detected in ampoules containing the recombinant material. Use of a common standard of PSA 90:10 significantly reduced the between-laboratory geometric coefficients of variation for serum samples included in the study and gave a much narrower range of potency estimates. Conclusions: The preparation of free PSA was established by WHO as the First International Standard for PSA (free) with an assigned content of 1 μg of total PSA per vial. In addition, the preparation of bound PSA was established as the First International Standard for PSA (90:10) with an assigned content of 1 μg of total PSA per vial.

Sign in / Sign up

Export Citation Format

Share Document