Abbott i-STAT 1 System Manual - page 514
CK-MB - 4
Art:
716675-00L
Rev. Date: 03-Aug-12
Method Comparison (ng/mL)
Abbott AxSYM
n
263
Sxx
1.84
Syy
2.66
Slope
1.01
Int’t
-0.19
Sy.x
3.98
Xmin
0.04
Xmax
224
r
0.994
Analytical Sensitivities
The sensitivity of the CK-MB method is 0.6 ng/mL, which is the lowest CK-MB level that can be
distinguished from zero. The analytical sensitivity is defined as two standard deviations associated with
a zero calibrator. The analytical sensitivity was estimated using a control material with < 1 ng/mL CK-
MB during a 20 day precision study in which three separate lots of CK-MB test cartridges were tested in
duplicate using a pool of 6 i-STAT 1 analyzers for a total of 120 test results.
Analytical Specificity
The CK-MB method is specific for the creatine kinase MB isoenzyme. The following muscle proteins
were tested and found to have an insignificant effect on the measured CK-MB.
Crossreactant
Concentration
Percent Crossreactivity
CK-MM (skeletal)
10000 ng/mL
Not Detectable
CK-BB (brain)
100 ng/mL
Not Detectable
Recovery
The dilution linearity of the i-STAT CK-MB test was investigated using heparinized whole blood and
plasma samples derived from 3 separate donors. For each donor, the original CK-MB negative sample
and a CK-MB spiked sample were prepared. This process yielded three CK-MB positive whole blood
samples that were then assayed in duplicate for each of three separate i-STAT CK-MB cartridge lots.
These whole blood samples were then diluted using an equal mass of the original unspiked whole blood
and assayed in duplicate. From this whole blood data, the CK-MB recovery was calculated.
The plasma derived from these three donors was combined in equal masses and all pairwise
combinations. These combinations were then assayed in duplicate for each of three separate i-STAT
CK-MB cartridge lots. The CK-MB recovery for each pair was calculated using the average of the 6
results. The % recoveries are listed in the Tables below.