Name
SAA, Human, ELISA kit
Catalog nr
HK333
(lot number and expiry date are indicated on the label)
Short description
Serum Amyloid A (SAA) is the circulating precursor of amyloid A protein. In humans, four SAA genes have been described. Two genes ( SAA1 and SAA2 ) encode acute phase SAA (A-SAA). SAA3 is a pseudogene from which no mRNA or protein product has been identified. SAA4 encodes constitutive SAA (C-SAA). SAA is 20 kDa in size, 12.5 kDa under denaturing conditions. The liver is the...
Size
2 x 96 det.
Application
Manual
Description
Serum Amyloid A (SAA) is the circulating precursor of amyloid A protein. In humans, four SAA genes have been described. Two genes (SAA1 and SAA2) encode acute phase SAA (A-SAA). SAA3 is a pseudogene from which no mRNA or protein product has been identified. SAA4 encodes constitutive SAA (C-SAA).
SAA is 20 kDa in size, 12.5 kDa under denaturing conditions. The liver is the primary site of synthesis of SAA. Extra-hepatic production has been demonstrated in macrophages, endothelial cells, epithelial cells, artherosclerotic lesions, tumors and synovial tissue. SAA-1 is the major isoform of SAA in plasma. SAA-1 levels in serum/plasma of healthy individuals range from 1-5 µg/ml.
SAA has a number of immunomodulatory roles, it can induce chemotaxis and adhesion molecule expression, has cytokine-like properties and can promote the upregulation of metalloproteinases. It enhances the binding of high-density lipoprotein to macrophages and thus assists in the delivery of lipids to sites of injury for use in tissue repair. It is thus thought to be an integral part of the disease processes. In addition, SAA is involved in cholesterol transport and metabolism.
SAA is an acute phase reactant and has been found to be elevated in many inflammatory states. The best known indicator of inflammation is C-reactive protein (CRP). However, SAA rises earlier and more sharply than CRP. In contrast to CRP, SAA presents the same trend in viral as well as bacterial infections. SAA increases dramatically during acute inflammation and may reach levels 1000-fold higher than normal.
Furthermore, SAA is an early indicator for transplant rejection, a possible marker for tumor activity and clinically useful in bacterial and viral infection. Elevated levels of SAA over time predispose to secondary amyloidosis, extracellular accumulation of amyloid fibrils, derived from a circulating precursor, in various tissues and organs. The most common form of amyloidosis occurs secondary to chronic inflammatory disease, particularly rheumatoid arthritis. The human SAA ELISA can be used for the measurement of SAA-1, the major isoform of SAA in plasma.
SAA is 20 kDa in size, 12.5 kDa under denaturing conditions. The liver is the primary site of synthesis of SAA. Extra-hepatic production has been demonstrated in macrophages, endothelial cells, epithelial cells, artherosclerotic lesions, tumors and synovial tissue. SAA-1 is the major isoform of SAA in plasma. SAA-1 levels in serum/plasma of healthy individuals range from 1-5 µg/ml.
SAA has a number of immunomodulatory roles, it can induce chemotaxis and adhesion molecule expression, has cytokine-like properties and can promote the upregulation of metalloproteinases. It enhances the binding of high-density lipoprotein to macrophages and thus assists in the delivery of lipids to sites of injury for use in tissue repair. It is thus thought to be an integral part of the disease processes. In addition, SAA is involved in cholesterol transport and metabolism.
SAA is an acute phase reactant and has been found to be elevated in many inflammatory states. The best known indicator of inflammation is C-reactive protein (CRP). However, SAA rises earlier and more sharply than CRP. In contrast to CRP, SAA presents the same trend in viral as well as bacterial infections. SAA increases dramatically during acute inflammation and may reach levels 1000-fold higher than normal.
Furthermore, SAA is an early indicator for transplant rejection, a possible marker for tumor activity and clinically useful in bacterial and viral infection. Elevated levels of SAA over time predispose to secondary amyloidosis, extracellular accumulation of amyloid fibrils, derived from a circulating precursor, in various tissues and organs. The most common form of amyloidosis occurs secondary to chronic inflammatory disease, particularly rheumatoid arthritis. The human SAA ELISA can be used for the measurement of SAA-1, the major isoform of SAA in plasma.
Cross Reactivity
Potential cross-reacting proteins detected in the human SAA ELISA:
|
Cross reactant |
Reactivity |
|
Human SAP |
negative |
|
Human PTX3 |
negative |
Features
Working time of 2½ hours.
Minimum concentration which can be measured is 3.1 ng /ml.
Measurable concentration range of 3.1 to 200 ng/ml.
Working volume of 100 µl/well.
Minimum concentration which can be measured is 3.1 ng /ml.
Measurable concentration range of 3.1 to 200 ng/ml.
Working volume of 100 µl/well.
Typical standard curve
Principle
- The human SAA ELISA is a ready-to-use solid-phase enzyme-linked immunosorbent assay based on the sandwich principle with a working time of 2½ hours.
- The efficient format of 2 plates with twelve disposable 8-well strips allows free choice of batch size for the assay.
- Samples and standards are incubated in microtiter wells coated with antibodies recognizing human SAA.
- Peroxidase conjugated antibody will bind to the captured human SAA.
- Peroxidase conjugated antibody will react with the substrate, tetramethylbenzidine (TMB).
- The enzyme reaction is stopped by the addition of oxalic acid.
- The absorbance at 450 nm is measured with a spectrophotometer. A standard curve is obtained by plotting the absorbance (linear) versus the corresponding concentrations of the human SAA standards (log).
- The human SAA concentration of samples, which are run concurrently with the standards, can be determined from the standard curve.
Use
The human SAA ELISA kit is to be used for the in vitro quantitative determination of human SAA-1 in serum, plasma, and urine samples. This kit is intended for laboratory research use only and is not for use in diagnostic or therapeutic procedures.
Storage and stability
- Upon receipt, store individual components at 2 - 8°C. Do not freeze.
- Do not use components beyond the expiration date printed on the kit label.
- The standard and conjugate are stable in lyophilized form until the expiration date indicated on the kit label, if stored at 2 - 8°C.
- The exact concentration of the standard is indicated on the label of the vial and the certificate of analysis.
- After reconstitution the standard must be used within 1 hour, the standard can not be stored for repeated use.
- Once reconstituted, conjugate is stable for 1 month if stored at 2 - 8°C.
- Upon receipt, foil pouch around the plate should be vacuum-sealed and unpunctured. Any irregularities to aforementioned conditions may influence plate performance in the assay.
- Return unused strips immediately to the foil pouch containing the desiccant pack and reseal along the entire edge of the zip-seal. Quality guaranteed until expiration date if stored at 2 - 8°C.
References
- Hazenberg B, et al; A quantitative method for detecting deposits of amyloid A protein in aspirated fat tissue of patients with arthritis. Ann Rheum Dis 1999, 58: 96
References
- Hazenberg B, et al; A quantitative method for detecting deposits of amyloid A protein in aspirated fat tissue of patients with arthritis. Ann Rheum Dis 1999, 58: 96
Scientific info
Human acute phase Serum Amyloid A protein, SAA, as inflammatory marker
Human SAA ELISA for detection in urine, plasma and serum
Human SAA and inflammation
- Serum amyloid A (SAA) is predominantly produced by the liver
- Extra-hepatic production by macrophages, endothelial cells, epithelial cells, artherosclerotic lesions, tumors and synovial tissue
- Four different genes in human produce SAA. SAA-1 is the predominant form in plasma
- SAA is a major acute phase protein
- Belongs to family of pentraxins (i.e. PTX3, CRP)
- SAA functions as chemo-attractant
Human SAA detection in urine
- To exclude matrix influence, urine with low SAA (#3) and urine with higher SAA (#4) concentration were mixed in different ratios
- The calculated concentration of human SAA was plotted versus the expected concentration of human SAA (Fig 1)
Evaluation of matrix-influence Human SAA and disease 
Hallmarks of human SAA ELISA (Cat# HK333)
- Unique assay for measurement in urine
- Human SAA concentration rises earlier and sharper than acute phase protein CRP
- Human SAA is increased after bacterial as well as viral infection
- Benchtop stability of standard > 95% (2 hrs RT; o/n 4 °C)
- Working time of 2.5 hours
- 100 µl sample/well
- Detection limit 3.1 ng/ml
- Useful for serum, plasma, fat-biopts and urine
- Detection of natural SAA-1
- Normal values in serum and plasma range from 1-5 µg/ml
- Acute inflammation may results in 1000-fold increase in human SAA
| Related products | Cat # | |
|---|---|---|
| LBP, Human, ELISA kit | HK315-02 | |
| Pentraxin 3, Human, ELISA kit | HK347 | |