Table l. Concent r a t ions are s pecified in the fi nal reaction
o
mixtur e a t 37 C, to ensure tha t max i mal CK c a ta ly t i c a ctivi -
o
o
ty will be s upporte d a t b oth 37 C and 30
c .
Stage A. Incubation-activation with reagent A.
Volume fraction in:
incubation-activation stage
complete reaction mixture
Imidazole pH 6.50
100.0
EDTA
2.0
N-acetylcysteine (NAC}
20.0
Magnesium acetate
10.0
ADP
2.0
AMP
5.0
Pl,P5-diAP
10.0
D-Glucose
20.0
NADP
2.0
Hexokinase (4000 U/L)
>..-
65
G-6-PHD
(2800 U/L)
>/
46
Add sample.
Volume fraction in reagent A:
0.952
0.870
mmol/L
mmol/L
mmol/1
mmol/L
mmol/L
mmol/L
)liDOl/L
mmol/L
mmol/L
)lkat/L
pkat/L
Volume fraction in complete mixture
0.0476
0.0435
Mi x carefully. Prior t o start o f t h e re a cti on
the CK enzyme pro tei n s ar e max i mal ly act i vat e d
by N-acety lcy steine with in 180 s.
With i n this time therma l equil i bration ha s to
be reached.
Stage B.
Substrate start with reagent B:
Creatine phosphate.
Volume fraction
Creatine phosphate
0.087
30 mmol/L
Mix ca r eful l y. Aftet· a lag phase of up to 6 0 s
a eonstant r eaction rate is achieved that is
monito re d fo r the minimum time and number of
data point s to obtain acceptable precision a –
r ound t he upper · reference limit .
Example of
volume
(pL}:
1000
pL
50
pL
100 pL
20
Klinisk kemi
i
Norden 2: suppl, / 990
