Quantitative determination of creatine kinase liquid (CK)
IVD
Store at 2-8ºC
CLINICAL SIGNIFICANCE
Creatine kinase is a cellular enzyme with wide tissue distribution in the body.
Its physiological role is associated with adenosine triphosphate (ATP)
generation for contractile or transport systems.
Elevated CK values are observed in diseases of skeletal muscle and after
myocardial infarction1,5,6,7.
Clinical diagnosis should not be made on a single test result; it should
integrate clinical and other laboratory data.
CONTROL
Lyophilized human
serum
PRECAUTIONS
R1: H360-May damage fertility or the unborn child. Contains: Imidazole
(C3H4N2)
Follow the precautionary statements given in MSDS and label of the
product.
PREPARATION
Mix 4 volumes of R1 with 1 volume of R2.
Stability: 2 weeks at 2-8ºC or 48 hours at room temperature (15-25ºC).
STORAGE AND STABILITY
All the components of the kit are stable until the expiration date on the label
when stored tightly closed at 2-8ºC, protected from light and contaminations
prevented during their use.
Signs of reagent deterioration:
- Presence of particles and turbidity.
- Blank absorbance (A) at 340 nm 1,00.
ADDITIONAL EQUIPMENT
- Spectrophotometer or colorimeter measuring at 340 nm.
- Thermostatic bath at 25ºC, 30ºC ó 37º C ( 0,1ºC).
- Matched cuvettes 1,0 cm light path.
- General laboratory equipment.
SAMPLES
Serum free of hemolysis or heparin plasma.
Stability 7 days at 2-8ºC, protected from light.
The creatin kinase activity decreases 10% after 1 day at 2-5ºC or after
1 hour at 15-25ºC.
QUALITY CONTROL
Control sera are recommended to monitor the performance of assay procedures:
SPINTROL H Normal and Pathologic (Ref. 1002120 and 1002210).
If control values are found outside the defined range, check the instrument,
reagents and technique for problems.
Each laboratory should establish its own Quality Control scheme and corrective
actions if controls do not meet the acceptable tolerances.
REFERENCE VALUES
25ºC 30ºC 37ºC
Men, up to 80 U/L 130 U/L 195 U/L
Women, up to 70 U/L 110 U/L 170 U/L
These values are for orientation purpose; each laboratory should establish its own
reference range.
PERFORMANCE CHARACTERISTICS
Measuring range: From detection limit of 2,12 U/L to linearity limit of 2000 U/L.
If the results obtained were greater than linearity limit, dilute the sample 1/10 with
NaCl 9 g/L and multiply the result by 10.
Precision: Intra-assay Inter-assay
Mean (U/L) 147 494 145 485
SD 1,23 3,60 2,91 8,97
CV (%) 0,84 0,73 2,01 1,85
Sensitivity: 1 U/L = 0,00012 A/min.
Accuracy: Results obtained using SPINREACT reagents (y) did not show
systematic differences when compared with other commercial reagents (x).
The results obtained were the following:
Correlation coefficient (r)2: 0,9995
Regression equation: y= 1,0846x – 0,3512.
The results of the performance characteristics depend on the analyzer used.
INTERFERENCES
No interferences were observed with glucose until 7 g/L, hemoglobin until 5 g/L
and triglycerides 7 mmol/L.
A list of drugs and other interfering substances with CK determination has been
reported3,4.
NOTES
SPINREACT has instruction sheets for several automatic analyzers.
Instructions for many of them are available on request.
