Precision and long-term stability of capillary electrophoresis measurement of serum protein zones.
BACKGROUND
Analytical evaluations of an available system for capillary zone electrophoresis (CZE) of serum protein have been reported. However, data concerning long-term precision and stability of the system, operated under routine conditions, are lacking. We report data from an internal quality control (QC) scheme, obtained over a 1-year period.


METHODS
Measurements were done with a pair of instruments (Beckman Paragon CZE 2000 system), each equipped with seven capillaries. After preliminary (1 month) assessment of possible inter-capillary and inter-instrument variations, the QC material (a home prepared serum pool stored in the frozen state) was assayed daily over a 1-year period.


RESULTS
Maximum inter-capillary and inter-instrument differences were 3.1% and 2.4%. No significant trend was observed for daily values (205 measurements over 1 year); in the same period overall imprecision values (CV) were in the interval 1.2% (albumin) to 3.2-6.1% (globulin zones). Mean monthly imprecision (CV) values were in the interval 1.1% (albumin) to 5.2% (globulin zones). There was no significant trend of monthly means with time. The observed imprecision values were within the biological variation-derived goals for imprecision.


CONCLUSIONS
It is concluded that the assessed analytical instruments, operated in routine conditions, show long-term stability and imprecision consistent with the clinical use of the results produced.
Luraschi
Paola
P
Laboratorio di Chimica Clinica, Ospedale L. Sacco, Milan, Italy.
Brambilla
Simona
S
Infusino
Ilenia
I
Franzini
Carlo
C
D001798:Blood Proteins / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D011786:Quality Control; D012016:Reference Values; D015203:Reproducibility of Results
D001798:Blood Proteins