Automated determination of creatine kinase activity in serum with use of thermostable glucokinase.
We measured creatine kinase (CK, EC 2.7.3.2) activity in serum with a new reagent system utilizing thermostable glucokinase (EC 2.7.1.2). Automated determinations were performed with Toshiba's Model TBA-80S Biochemical Analyzer. Precision studies demonstrated within-run and between-run CVs of 0.4%-2.4% and 2.8%-3.1%, respectively. The response linearity was confirmed for CK activity up to 1000 U/L at 37 degrees C. CK activities correlated well (r = 0.997) with those obtained by the manual method recommended by the German Society for Clinical Chemistry (measuring at 37 degrees C) involving hexokinase (EC 2.7.1.1). However, CK activities measured by our method were consistently higher than those of the hexokinase method at reaction temperatures of 30, 37, and 40 degrees C. These data indicate that the new method with thermostable glucokinase is better than that with thermo-unstable hexokinase for determination of CK activity in serum.
Maeda
I
I
Central Laboratory for Clinical Investigation, Osaka University Hospital, Japan.
Hayashi
S
S
Amino
N
N
Miyai
K
K
D001331:Automation; D003402:Creatine Kinase / Q000097:blood*; D005941:Glucokinase; D006593:Hexokinase; D006358:Hot Temperature; D006801:Humans; D011933:Reagent Kits, Diagnostic
D011933:Reagent Kits, Diagnostic; D006593:Hexokinase; D005941:Glucokinase; D003402:Creatine Kinase