J Clin Pathol Qual Control.  1999 Jun;21(1):209-215.

A Study on Home Made Lyophilized Plasma for Quality Control

• Lee WS

Abstract

BACKGROUND: The use of frozen plasma is possible for internal quality control. Lyophilized plasma is expensive and is currently imported from abroad. The aim of present study was to prepare lyophilized plasma and to determine whether it was applicable to external quality control. METHOD: Plasma from normal individuals and from patients on oral anticoagulants were mixed respectively, aliquotted into volumes of 1 mL, and lyophilized. To test the homogeneity of the vials, 12 vials of lyophilized plasma from normal individuals (NLP) and 12 from patients on oral anticoagulants (ALP) were tested for prothrombin time (PT) and activated partial thromboplastin time (aPTT) and the coefficient variation (CV) was calculated from the results. The PT and aPTT were also measured at each part of the process to determine the changes that might occur. After reconstitution of the lyophilized plasma, PT and aPTT were measured after the samples were stored at 4degrees C, room temperature, and 37degrees C
RESULTS
In NLP, the PT was 11.7 sec (CV 1.1%) and aPTT was 23.8 sec (CV 1.0%). For ALP, the PT was 18.1 sec (CV 2.4%) and aPTT was 36.0 sec (CV 1.6%), there was an increase in the aPTT during the lyophilization process of patients on oral anticoagulants. The samples were stable for a month at 4degrees C or room temperature and for 5 days at 37degrees C
CONCLUSION
Our hone-made lyophilized vials were homogeneity and were stable for a month when stored at 4degrees C or room temperature, which makes them suitable for use in external quality control.

MeSH Terms

Anticoagulants
Freeze Drying
Humans
Partial Thromboplastin Time
Plasma*
Prothrombin Time
Quality Control*
Anticoagulants