J Clin Pathol Qual Control.  1999 Jun;21(1):175-180.

Lyophilized Quality Control Material for Clinical Chemistry and Coagulation

• Park H
• Lee DH
• Yoon YM
• Jung HJ
• Song J
• Park SS
• Kim JQ

Abstract

BACKGROUND: Quality control material is essential reagent/material for maintaining the precision of clinical laboratory analysis. The manufacturing effort or study of the quality control material in Korea is in its starting stage and almost all laboratories in Korea is using the imported diagnostic quality control material made by foreign multinational in-vitro diagnostics companies. This study aimed at producing and evaluating the quality control material in lyophilized form for clinical chemistry and coagulation. METHOD: Pooled sera or plasma were filtered with Milipore filter-system at 0.5 micrometer and 0.22 micrometer with Milipore filter system. Then 3 mL (1 mL for coagulation) of them were aliquoted into 15 mL cryovials with repeating pipet and frozen at -70degrees C. Frozen vials were lyophilized with lyophilizer and capped with split stopper in vacuum and done aluminum sealing. After storage at 4degrees C, the evaluation for precision, turbidity, and solubility were carried out.
RESULTS
The precision of aliquoting were done with weighing the vial and split stopper before and after aliquoting. The coefficient of variation of aliquoting precision were 0.378%. Between day CV for lyophilized house made material for clinical chemistry was 3.84% which were slightly higher than those of lyophilized commercial material at 2.15% and frozen house made material at 2.55%. For coagulation, house made quality control materials were divided into 3 ranges; normal, abnormal I, and abnormal II. They showed low CV values especially in prothrombin Time test, which is main target for standardization and quality control. Freeze dried material for normal showed CV value of 1.9%.
CONCLUSION
This study showed acceptable results for house made lyophilized quality material for clinical chemistry and coagulation in between day precision and lyophilization process including aliquoting. But for a few test items, further study for stability and homogeneity is warranted.

MeSH Terms

Aluminum
Chemistry, Clinical*
Freeze Drying
Korea
Plasma
Prothrombin Time
Quality Control*
Solubility
Vacuum
Aluminum