| CSTA

Cystatin-A is a protein that in humans is encoded by the CSTA gene.The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. There are three inhibitory families in the superfamily, including the type 1 cystatins (stefins), type 2 cystatins, and kininogens. This gene encodes a stefin that functions as a cysteine protease inhibitor, forming tight complexes with papain and the cathepsins B, H, and L. The protein is one of the precursor proteins of cornified cell envelope in keratinocytes and plays a role in epidermal development and maintenance.
 

| 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)	20	10	5	2.5	1.25	0.62	0.31	0
OD	2.14	1.63	1.16	0.78	0.57	0.43	0.24	0.07
Corrected OD	2.07	1.56	1.09	0.71	0.5	0.36	0.17	-

 

| Repeatability

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

| Recovery

The recovery of Human CSTA 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)	84-101	96
Plasma(n=8)	93-105	102
Cell Culture Supernates(n=8)	96-108	105

 

| Linearity

Samples were spiked with high concentrations of Human CSTA 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	92-110
	Average (%)	91	93	96
1 : 4	Range (%)	88-103	87-108	105-115
	Average (%)	94	98	108