Sample evaporation from pierceable cups: still an important source of analytical error.

Author(s): Schouwers S, Cuypers E, Vervaet S, Uyttenbroeck W, Neels H

Publication: Clin Biochem, 2010, Vol. 43, Page 1464-7

PubMed ID: 20850427 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 evaporation during storage of serum specimens on sodium, calcium, glucose and HCO3. Specimens were aliquoted into the various open and closed containers within 45 minutes of blood draw.

   Summary of Findings:

   When serum was stored in open cups for 15 minutes or in cups with pierceable lids for 30 minutes, sodium levels increased compared to specimens in covered polystyrene tubes, but no effect on sodium levels was found when specimens were stored in uncovered serum tubes. Calcium levels increased in specimens stored for 30 minutes in open cups or 250 ul specimens capped with a pierceable lid. Increased calcium was also found after 60 minutes when 500 ul specimens were stored with a pierceable lid, and after 120 minutes when specimens were stored in an uncovered serum tube. Glucose levels increased in specimens stored in open cups for 60 minutes, or in 250 ul specimens stored in cups with pierceable lids for 120 minutes. No change in glucose was found in 500 ul specimens stored in cups with pierceable lids, or in specimens stored in open serum tubes. HCO3 decreased after 30 minutes when stored in cups either uncovered or with a pierceable lid or in uncapped serum tubes compared to specimens stored in covered polystyrene tubes. Specimens stored in open serum tubes remained within the reference range for all analytes regardless of storage duration, but after 30 minutes, specimens stored in open or closed cups had exceeded the reference range for one or more analytes.

   Biospecimens

   • Bodily Fluid - Serum

   Preservative Types

   • None (Fresh)

   Diagnoses:

   • Normal

   Platform:

   Analyte	Technology Platform
   Carbohydrate	Clinical chemistry/auto analyzer
   Electrolyte/Metal	Clinical chemistry/auto analyzer

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Time at room temperature	0 min 15 min 30 min 60 min 120 min
   Biospecimen Aliquots and Components	Aliquot size/volume	250 ul 500 ul
   Storage	Storage conditions	Covered Covered with pierceable lid Uncovered
   Storage	Type of storage container	Vitros microsample cup Serum tube Polystyrene tube

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