The effect of storage at different temperatures on the stability of Hepatitis C virus RNA in plasma samples.

Author(s): José M, Curtu S, Gajardo R, Jorquera JI

Publication: Biologicals, 2003, Vol. 31, Page 1-8

PubMed ID: 12623054 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the effects of dilution and storage temperature and duration on plasma HCV load quantification by Amplicor Monitor (PCR assay) and Quantiplex (branched DNA assay). A single specimen with an initial viral load of 591,667 international units (IU)/mL was diluted with a nonreactive fractionation plasma pool to produce the values studied. Frozen specimens were thawed at 30 degrees C.

   Summary of Findings:

   The HCV titer in the undiluted specimens, as determined by the Amplicor assay, was unaffected by frozen storage at -20 or -70 degrees C for up to 999 days but declined, as determined by Quantiplex, in undiluted specimens stored at -20 degrees C, with a half-life of 811 days. While a significant decline in titer was noted in specimens diluted to 42,675 copies HCV/mL or 72,004 copies HCV/mL that were stored at -20 and -70 degrees C, there was no significant effect of titer on decay rate. Generally, all 3 replicate undiluted specimens tested positive for HCV at each timepoint (0-909 days), but with increasing dilution, the number of positives at each timepoint decreased slightly. HCV load in specimens stored at 5 degrees C had a half-life of 81 (lower titer)-84 (higher titer) days, and HCV load in specimens stored at 25 degrees C had a half-life of 14 days in specimens diluted to 42,675 copies HCV/mL or 72,004 copies HCV/mL.

   Biospecimens

   • Bodily Fluid - Plasma

   Preservative Types

   • Frozen
   • None (Fresh)
   • Other Preservative

   Diagnoses:

   • Hepatitis

   Platform:

   Analyte	Technology Platform
   RNA	Branch DNA assay
   RNA	RT-PCR

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Storage duration	0-56 days 0-168 days 0-909 days 0-938 days 0-999 days
   Storage	Storage temperature	-70 degrees C -20 degrees C 5 degrees C 25 degrees C
   Biospecimen Preservation	Type of fixation/preservation	Frozen None (fresh) Refrigeration
   RT-PCR Specific	Technology platform	Quantiplex branched DNA assay
   Preaquisition	Biomarker level	42,675 copies HCV/mL 72,004 copies HCV/mL
   Biospecimen Aliquots and Components	Aliquot size/volume	Undiluted 1:2 dilution 1:4 dilution 1:8 dilution

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