DiaMetra CIC C1q Elisa Kit

INTENDED PURPOSE
CIC C1q ELISA is a manual in vitro diagnostic device intended for the quantitative determination of CIC C1q in human serum or plasma from an adult population.

CLINICAL SIGNIFICANCE
The complement system is a biochemical cascade of the immune system that helps clear pathogens from an organism. It is derived from many small plasma proteins that work together to form the primary end result of cytolysis by disrupting the target cell's plasma membrane.
Activation of this system leads to cytolysis, chemotaxis, opsonization, immune clearance, and inflammation, as well as the marking of pathogens for phagocytosis. The complement system consists of more than 35 soluble and cell-bound proteins, 12 of which are directly involved in the complement pathways. The proteins account for 5% of the serum globulin fraction. The complement proteins are synthesized mainly by hepatocytes; however, significant amounts are also produced by monocytes, macrophages, and epithelial cells in the gastrointestinal and genitourinary tracts.
C1q is involved in the classical complement pathway. The classical pathway is triggered by activation of the C1- complex (which consists of one molecule C1q and two molecules C1r and C1s), either by C1q's binding to antibodies from classes M and G, complexed with antigens, or by its binding C1q to the surface of the pathogen.
The complement system might play a role in many diseases with an immune component, such as Barraquer-Simons Syndrome Alzheimer's disease, asthma, lupus erythematosus, various forms of arthritis, autoimmune heart disease and multiple sclerosis. Deficiencies in the terminal pathway predispose to both autoimmune disease and infections (particularly meningitis).
There are many tests for the determination of CIC, included the test of precipitation with PEG, radial immunodiffusion, and cellular tests like the test of Ray cell. Does not exist one procedure to determinate all types of immunocomplex; in commerce exist some test to determinate fragments of the complex (e.g. C1q and C3d) that have an important diagnostic function.

PRINCIPLE OF THE METHOD
CIC C1q ELISA kit is based on the binding of C1q-linked immunocomplexes to C1q adsorbed on microplate. In the first step, the samples are added to the microplate adsorbed with C1q; during the following incubation, C1q-fixing circulating immune complexes (CIC) bind to the C1q immobilized on the microplate. The microplate is washed for remove the unbound serum proteins.
In the second step, the anti-human IgG conjugated with horseradish peroxidase (HRP) is added; it binds to the immunocomplex fixed on the microplate. The washing step removes the unbound conjugate.
In the third step, the TMB Substrate is added, and this reacts with the conjugate fixed on the microplate, developing a colorimetric reaction. The quantity or CIC IgG complex is proportional to the colour intensity read at 450 nm wavelengths.
The immunocomplex concentration in the sample is calculated through a calibration cuve. Heat aggregate human gamma globulin per mL (μgEq/mL) is the unit of measure of the results.

REAGENT STORAGE AND STABILITY
Store the kit at 2 – 8°C in the dark. 
The kit is stable at 2 – 8°C until the expiry date stated on the external kit label.
Once opened, the kit is stable at 2 – 8°C for 6 months.
The diluted wash solution is stable for 30 days at 2 – 8°C. 
In use stability data supports reagent stability when used three times within this period.
Important note: open the bag containing the Coated Microplate only when it is at room temperature and close it immediately after use.

SAMPLE COLLECTION AND STORAGE
The assay should be performed using serum (standard sampling tubes or tubes containing serum separating gel) or plasma (lithium heparin, sodium heparin or potassium EDTA) samples.

CALCULATION OF RESULTS
A variety of data reduction software packages are available, which may be employed to generate the mean calibration curve and to calculate the mean concentrations of unknown samples and controls. A best fit curve, including Calibrator 0 is required. Other curve fitting algorithms are not recommended.
Alternatively, a calibration curve may be prepared on semilog graph paper by plotting mean absorbance on the Y-axis against concentration of analyte on the X-axis. Calibrator 0 should be included in the calibration curve. Read the mean absorbance value of each unknown sample off the curve.
In order for the assay results to be considered valid the kit calibrators and control must fall within the specifications detailed in the lot specific certificate of analysis.
If a control is out of its specified range, the associated test results are invalid and samples must be retested.

QUALITY CONTROL
Good Laboratory Practice (GLP) requires the use of quality control specimens in each series of assays in order to check the performance of the assay. Controls should be treated as unknown samples, and the results analysed with appropriate statistical methods.
The kit controls provided in the kit should be tested as unknowns and are intended to assist in assessing the validity of results obtained with each assay plate.
The mean concentration of each control level is documented in the QC report included with each kit. These mean concentration levels are determined over several assays which are run in duplicate in multiple locations across each plate.

LIMITATIONS OF USE
As in the case of any diagnostic procedure, results must be interpreted in conjunction with the patient’s clinical presentation and other information available to the physician. 
The performance characteristics of this assay have not been established in a paediatric population. Heterophilic antibodies in human serum can react with reagent immunoglobulins, interfering with in vitro immunoassays. Patients routinely exposed to animals or to animal serum products can be prone to this interference and anomalous values may be observed.