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.
INTENDED USE
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.
SUMMARY
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
PRINCIPLE
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.
For SAA
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.
For CRP
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.
QUALITY CONTROL
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.
Order Information
| Cat. No. | Product | Specimen | Pack |
| OCSC-425 | SAA and CRP Combo Rapid Test Cassette | WB/S/P | 10T |
| OSA-402 | SAA Rapid Test Cassette | WB/S/P | 10 T |
