Different stability of free and complexed prostate-specific antigen in serum in relation to specimen handling and storage conditions.

Author(s): Jung K, Lein M, Brux B, Sinha P, Schnorr D, Loening SA

Publication: Clin Chem Lab Med, 2000, Vol. 38, Page 1271-5

PubMed ID: 11205692 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine if a delay in separation at room temperature affects detectable levels of fPSA, tPSA, and ACT-PSA in serum.

   Summary of Findings:

   A room temperature delay in separation resulted in a 3-5% decrease in serum fPSA levels after 4 hours, respectively. tPSA and ACT-PSA were stable at room temperature for up to 24 hours prior to serum separation.

   Biospecimens

   • Bodily Fluid - Serum
   • Bodily Fluid - Blood

   Preservative Types

   • Frozen

   Diagnoses:

   • Neoplastic - Benign
   • Neoplastic - Carcinoma

   Platform:

   Analyte	Technology Platform
   Protein	Immunoassay

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Time at room temperature	1 h 2 h 4 h 8 h 24 h
   Biospecimen Aliquots and Components	Centrifugation	Centrifugation delays investigated

   View more

2. Study Purpose

   The purpose of this study was to determine if a delay post-separation at varying temperatures affects detectable tPSA, fPSA, and ACT-PSA serum levels. Freeze-thaw cycling of immediately processed and frozen serum specimens was also investigated.

   Summary of Findings:

   Storage of separated serum at 37 degrees C resulted in a decrease in tPSA, ACT-PSA, and fPSA by 5-8% after 8-24 hours, whereas storage at 4 degrees C resulted in significant decreases in fPSA and tPSA after 1 and 7 days, respectively. All PSA forms remained stable at -80 degrees C for up to 2 months. While a large degree of variability was observed for all PSA forms, multiple freeze-thaw cycles did not induce significant effects.

   Biospecimens

   • Bodily Fluid - Serum

   Preservative Types

   • Frozen

   Diagnoses:

   • Neoplastic - Benign
   • Neoplastic - Carcinoma

   Platform:

   Analyte	Technology Platform
   Protein	Immunoassay

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Storage duration	1 h 2 h 4 h 8 h 1 d 4 d 7 d 2 mon
   Storage	Storage temperature	Room temperature 4 degrees C 37 degrees C -80 degrees C
   Storage	Freeze/thaw cycling	0 cycles 1 cycle 3 cycles 5 cycles

   View more