A rapid test for the diagnosis of inflammatory condition by detecting Serum Amyloid A (SAA) and C-reactive protein qualitatively in whole blood, serum or plasma. For professional in vitro diagnostic use only.
The SAA and CRP Combo Rapid Test Cassette (Whole Blood/Serum/Plasma) is a rapid chromatographic immunoassay for the qualitative detection of human SAA and CRP in whole blood, serum or plasma as an aid in the diagnosis of inflammatory condition. The cutoff for SAA is 10 μg/mL and cut-off for CRP is 10 μg/mL.
Serum amyloid A (SAA) proteins are a family of apolipoproteins associated with high-density lipoprotein (HDL) in plasma. Different isoforms of SAA are expressed constitutively (constitutive SAAs) at different levels or in response to inflammatory stimuli (acute phase SAAs). These proteins are produced predominantly by the liver.1 The conservation of these proteins throughout invertebrates and vertebrates suggests that SAAs play a highly essential role in all animals.
Acute-phase serum amyloid A proteins (A-SAAs) are secreted during the acute phase of inflammation. These proteins have several roles, including the transport of cholesterol to the liver for secretion into the bile, the recruitment of immune cells to inflammatory sites, and the induction of enzymes that degrade extracellular matrix. Serum amyloid A (SAA) is also an acute phase marker that responds rapidly.
Similar to CRP, levels of acute-phase SAA increase within hours after inflammatory stimulus, and the magnitude of increase may be greater than that of CRP. Relatively trivial inflammatory stimuli can lead to SAA responses. It has been suggested that SAA levels correlate better with disease activity in early inflammatory joint disease than do ESR and CRP. Although largely produced by hepatocytes, more recent studies show that SAA is produced by adipocytes as well, and its serum concentration is
associated with body mass index.
C-reactive protein (CRP) is an annular (ring-shaped), pentameric protein found in blood plasma, whose levels rise in response to inflammation. It is an acute-phase protein of hepatic origin that increases following interleukin-6 secretion by macrophages and T cells. Its physiological role is to bind to lysophosphatidylcholine expressed on the surface of dead or dying cells (and some types of bacteria) in order to activate the complement system via C1q.
CRP plays a role in innate immunity by binding to the phosphocholine expressed on the surface of dead or dying cells and some bacteria. This activates the complement system, promoting phagocytosis by macrophages, which clears necrotic andapoptotic cells and bacteria.5
The SAA and CRP Combo Rapid Test Cassette has two parts. One part is for SAA and another one is for CRP. Both are qualitative, solid phase, two-site sandwich immunoassay for the detection of target analyte, i.e., SAA or CRP respectively in whole blood, serum or plasma.. In two separate sections below, principles for both are described.
The membrane is pre-coated with anti-SAA antibodies on the test line region of the cassette. During testing, SAA, if present in the specimen (whole blood, serum or plasma) above the cut-off level reacts with Colloidal Gold conjugated anti-SAA antibodies. The complex migrates upward on the membrane chromatographically by capillary action to react with anti-SAA antibodies on the membrane and generate a colored line. The presence of this colored line in the test region indicates a positive result, while its absence indicates a negative result. To serve as a procedural control, a colored line will always appear in the control line region indicating that proper volume of specimen has been added and membrane wicking has occurred.
The membrane is pre-coated with anti-CRP antibodies on the test line region of the cassette. During testing, CRP, if present the specimen (whole blood, serum or plasma) above the cut-off level reacts with the Colloidal Gold conjugated anti-CRP antibodies. The mixture migrates upward on the membrane chromatographically by capillary action to react with anti-CRP antibodies on the membrane and generate a colored line. The presence of this colored line in the test region indicates a positive result, while its absence indicates a negative result. To serve as a procedural control, a colored line will always appear in the control line region indicating that proper volume of specimen has been added and membrane wicking has occurred.
DIRECTIONS FOR USE
Bring tests, specimens, buffer, and/or controls to room temperature (15-30°C) before use.
1. Remove the Test Cassette from its sealed pouch, and place it on a clean, level surface. For best results, the assay should be performed within one hour.
2. Open the tube with the diluted sample .Transfer 3 drops of diluted sample (approximately 120 μL)
to each sample well(S) Start the timer.
3. Wait for the colored lines to appear. The result should be read at 5 minutes. Do not interpret the results after 10 minutes.
INTERPRETATION OF RESULTS
POSITIVE:* Two lines appear. One colored line should be in the control line region (C) and another apparent colored line should be in the test line region (T).
*NOTE: The intensity of the color in the test line region (T) will vary depending on the concentration of SAA antigen and/or CRP antigen present in the specimen. Therefore, any shade of color in the test line region (T) should be considered positive.
NEGATIVE: One colored line appears in the control line region (C). No line appears in the test line region (T).
INVALID: Control line fails to appear. Insufficient specimen volume or incorrect procedural techniques are the most likely reasons for control line failure. Review the procedure and repeat the test with a new test. If the problem persists, discontinue using the test kit immediately and contact your local distributor.
Internal procedural controls are included in the test. Control line appearing in the control regions is considered an internal positive procedural control, confirming sufficient specimen volume and correct procedural technique.
External controls are not supplied with this kit. It is recommended that positive and negative controls be tested as a good laboratory practice to confirm the test procedure and to verify proper test performance.
|SAA and CRP Combo Rapid Test Cassette
|SAA Rapid Test Cassette