Rapid Human Cystatin C ELISA kit

Rapid Human Cystatin C ELISA kit

SKU: 31241

 

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★ Download MSDS ★

 

Assay range :   0.23-15ng/ml

Size :                96T/Kit

 

  • INTRODUCTION

    C-reactive protein (CRP) is a circulating protein mainly secreted from the liver. This acute phase protein consists of five identical non-glycosylated subunits of 23 kDa, that give rise to a symmetrically arranged globular protein with molecular weight of approximately 120 kDa.1 It has long been recognized that CRP is closely related to immunology, inflammation and host defence; as a result it has been used as an inflammatory marker. However, the development of high-sensitivity CRP (hsCRP) ELISA had addressed its role in other clinical issues. There is accumulating evidence suggesting the important role that CRP plays in mediating cardiovascular diseases (CVD) and type 2 diabetes.2-4 Normally CRP is presenting only in a trace amount in circulation (<1 µg/ml)5,6 but can increase over 1,000-fold under acute inflammatory state. Individual with blood CRP levels <1 µg/ml, 1-3 µg/ml and >3 µg/ml is considered to have low, moderate and high risk, respectively, of CVD and myocardial infraction.7 Therefore, blood CRP level has become a promising measure of CVD risk.8,9

  • PRINCIPLE OF THE ASSAY

    This assay is a sandwich ELISA designed for the quantitative detection of human cystatin c in samples in 1 hour. The immunoplate is pre-coated with antibody specific to human cystatin c. Standards and samples are pipetted into the wells and any human cystatin c present is sandwiched by the immobilised antibody and a second horseradish peroxidase (HRP)-linked antibody specific to human cystatin c that is co-incubated with the samples.  After wash step to remove any unbound substances, the HRP substrate solution is added and colour develops in proportion to the amount of human cystatin c bound initially.  The assay is stopped and the optical density of the wells determined using a micro-plate reader. Since the increases in absorbance are directly proportional to the amount of captured human cystatin c, the unknown sample concentration can be interpolated from a reference curve included in each assay.

  • ASSAY PERFORMANCE

    A. Typical representation of standard curve

    The following standard curve is provided for demonstration only. A standard curve should be generated for each set of sample assay.  

    Cystatin c (ng/ml)

    Absorbance (450 nm)

    Blanked Absorbance

    0

    0.069

    0

    0.23

    0.127

    0.058

    0.46

    0.187

    0.118

    0.93

    0.309

    0.24

    1.87

    0.539

    0.47

    3.75

    0.946

    0.877

    7.5

    1.685

    1.616

    15

    2.551

    2.482

     

    B. Sensitivity:

    The lowest level of human cystatin c that can be detected by this assay is 0.23 ng/ml.

     

    C. Specificity:

    The antibodies used in this assay are specific to human cystatin c and do not cross-react with mouse and rat cystatin c, and other cytokine or hormone molecules.

     

    D. Precision:

    Intra-assay Precision (Precision within an assay)

    Three samples of known concentration were tested 12 times on one plate.

    Sample

    Mean (ng/ml)

    SD (ng/ml)

    CV (%)

    1

    507.3

    30.1

    5.9

    2

    377.2

    23.1

    6.1

    3

    137.4

    10.8

    7.9

    Inter-assay Precision (Precision between assays)

    Three samples of known concentration were tested in 10 separate assays.

    Sample

    Mean (ng/ml)

    SD (ng/ml)

    CV (%)

    1

    499.3

    39.0

    7.8

    2

    377.2

    23.1

    6.1

    3

    137.4

    10.8

    7.9

     

    E. Recovery:

    Serum samples were spiked with different amounts of human cystatin c and  assayed.

    Sample

    Average % Recovery

    Range %

    Serum 

    99

    94-107

$330.00Price

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