Split sample analysis of serum folate levels after 18 days in frozen storage.
Author(s): Lawrence JM, Umekubo MA, Chiu V, Petitti DB
Publication: Clin Lab, 2000, Vol. 46, Page 483-6
PubMed ID: 11034534 PubMed Review Paper? No
Purpose of Paper
Conclusion of Paper
Studies
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Study Purpose
The purpose of this study was to determine the effects of storage of serum for an additional 18 days at -20 degrees C in a frost-free freezer on folate levels. Prior to the start of the 18 days of storage, specimens were collected and transported at room temperature, and aliquoted and frozen at -20 degrees C for 3-11 days.
Summary of Findings:
After 18 days of additional storage at -20 degrees C, serum folate values decreased for the vast majority of specimens. An average decrease of 5.0 ug/L (p<0.0001) of serum folate was observed for specimens in the quantifiable range (0.25 ug/L to 39.9 ug/L, after 1:2 dilution, as necessary). For women who were taking vitamin supplements, initial folate levels were consequently higher, and the average decrease in serum folate after 18 days additional storage was 29%. On the other hand, for women who were not taking vitamins and had lower initial serum folate values, the average decrease after 18 days additional storage was only 13% (p<0.002).
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Pregnant
Platform:
Analyte Technology Platform Small molecule Clinical chemistry/auto analyzer Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Storage temperature -20 degrees C
Room temperature
Storage Storage duration 3-11 d
21-29 d
Preaquisition Other drugs Vitamins containing folic acid
No vitamin use