| CKMB

Creatine kinase MB isoenzyme (CKMB) is a dimer composed of brain subunit (B) and muscle subunit (M). Normal tissues usually contain three isoenzymes, which are CK-BB (CK1), CK-MB (CK2) and CK-MM (CK3) in order of electrophoresis speed. CKMB mainly exists in myocardial tissue, accounting for ~ 4% of CK in serum. After the release of CK-MB2 from the myocardium, the carboxyl terminal is hydrolyzed by plasma carboxyl peptidase N, and a lysine residue is removed to convert to the serum modified isoform CK-MB1. The increase of CK during myocardial injury is mainly caused by the increase of CKMB, which is manifested as the simultaneous increase of both.
 

| Typical data

As the OD values of the standard curve may vary according to the conditions of the actual assay performance (e.g. operator, pipetting technique, wash technique or temperature effects), the operator should establish a standard curve for each test. Typical standard curve and data are provided below for reference only.

 

Concentration (ng/mL)	100	50	25	12.5	6.25	3.12	1.56	0
OD	2.36	1.78	1.23	0.79	0.46	0.29	0.17	0.09
Corrected OD	2.27	1.69	1.14	0.7	0.37	0.2	0.08	-

 

| Repeatability

Intra-assay Precision (Precision within an assay)：CV% < 10%; Inter-assay Precision (Precision between assays)：CV% < 10%
 

| Recovery

The recovery of Rat CKMB spiked at three different levels in samples throughout the range of the assay was evaluated in various matrices.

 

Sample Type	Range(%)	Average Recovery(%)
Serum(n=8)	85-101	96
Plasma(n=8)	92-105	101
Cell Culture Supernates(n=8)	96-108	105

 

| Linearity

Samples were spiked with high concentrations of Rat CKMB and diluted with Universal Diluent to produce samples with values within the range of the assay.

 

		Serum(n=4)	Plasma(n=4)	Cell Culture Supernates(n=4)
1 : 2	Range (%)	84-95	88-96	90-110
	Average (%)	91	93	96
1 : 4	Range (%)	89-103	87-108	105-115
	Average (%)	94	98	108