Manual
Description
C1q forms together with C1r and C1s the C1 macromolecule, the first component of the classical complement pathway. The formation of an antibody–antigen complex (immune complex) is the principal way of activating the classical pathway of the complement system. C1q triggers the activation process when it docks onto antibodies within these immune complexes. In this way, C1q acts to bridge the innate and adaptive immune systems. Interaction of immune complexes with C1q induces a conformational change within the C1 complex, which results in activation of the classical pathway. C1q functions as recognition unit by binding to the heavy chain of IgG or IgM (Fc gamma and Fc micro) provided that the immunoglobulins are bound to their antigen. Furthermore, C1q can bind to apoptotic blebs, where it activates the classical complement pathway and mediates phagocytosis. As such, C1q promotes the clearance of apoptotic cells and subsequent exposure of auto-antigens, thereby preventing stimulation of the immune system. C1q is predominantly produced by macrophages but also by follicular dendritic cells, interdigitating cells and cells of the monocyte-macrophage lineage. C1q deficiency has a profound effect on host defense and clearance of immune complexes.
Inherited C1q deficiency is also associated with the development of systemic lupus erythematosus (SLE). In the case of C1q deficiency, SLE is found in 90% of reported cases. C1q plays a role in the prevention of autoimmunity by facilitating the physiological clearance and processing of apoptotic debris. Absence of C1q may cause autoimmunity by impairment of the clearance of apoptotic cells.Anti-C1q autoantibodies deposit in glomeruli together with C1q but induce overt renal disease only in the context of glomerular immune complex disease. This provides an explanation why anti-C1q antibodies are especially pathogenic in patients with SLE. Low C1q levels are associated with proliferative glomerulonephritis (WHO class III and IV). Furthermore, C1q concentrations decrease prior to clinical manifestations of flares of the disease. Low C1q levels have also been shown to predict the histopathological outcome of lupus nephritis. A single nucleotide polymorphism in the C1QA gene results in decreased C1q serum levels and has been linked to photosensitive Lupus-specific skin disease, subacute cutaneous lupus erythematosus (SCLE).
Cross Reactivity
| Cross reactant |
Reactivity |
| Human |
Strong |
| Rat |
Strong |
Features
- Working time of 3½ hours.
- Minimum concentration which can be measured is 15.6 ng/ml.
- Measurable concentration range of15.6 to 1000 ng/ml.
- Working volume of 100 µl/well.
Use
The mouse C1q ELISA kit is to be used for the in vitro quantitative determination of mouse C1q in serum and plasma samples. This kit is intended for laboratory research use only and is not for use in diagnostic or therapeutic procedures. The analysis should be performed by trained laboratory professionals.
Storage and stability
- Once reconstituted the standard is stable for 12 hours, if stored at 2 - 8°C. For longer stability we recommend to store aliquots at
–20°C. Stored at –20°C the standard will be stable for 1 month.
- Once reconstituted, tracer and streptavidin-peroxidase are 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.
Recovery
Normal mouse serum samples containing baseline levels of mouse C1q, were spiked with 50 and 250 ng purified human C1q (Complement Technology) ranged between 101% and 102.5%.
Linearity
The linearity of the assay was determined by serially diluting a sample containing mouse C1q. The diluted samples were measured in the assay.
Precautions
- For research use only, not for diagnostic or therapeutic use.
- This kit should only be used by qualified laboratory staff.
- Do not under any circumstances add sodium azide as preservative to any of the components.
- Do not use kit components beyond the expiration date.
- Do not mix reagents from different kits and lots. The reagents have been standardized as a unit for a given lot. Use only the reagents supplied by the manufacturer.
- The assay has been optimized for the indicated standard range.
- Do not ingest any of the kit components.
- Kit reagents contain 2-chloroacetamide as a preservative. 2-Chloroacetamide is harmful in contact with skin and toxic if swallowed. In case of accident or if you feel unwell, seek medical advise immediately.
- The TMB substrate is light sensitive, keep away from bright light. The solution should be colourless until use.
- The stop solution contains 2% oxalic acid and can cause irritation or burns to respiratory system, skin and eyes. Direct contact with skin and eyes should be strictly avoided. If contact occurs, rinse immediately with plenty of water and seek medical advise.
- Incubation times, incubation temperature and pipetting volumes other than those specified may give erroneous results.
- Do not reuse microwells or pour reagents back into their bottles once dispensed.
- Handle all biological samples as potentially hazardous and capable of transmitting diseases.
- Hemolyzed, hyperlipemic, heat-treated or contaminated samples may give erroneous results.
- Use polypropylene tubes for preparation of standard and samples. Do not use polystyrene tubes or sample plates.
- The standard is of human origin. It was tested for various viruses and found negative. Since no test method can offer complete assurance that infectious agents are absent, this reagent should be handled as any potentially infectious human serum or blood specimen. Handle all materials in contact with this reagent according to guide-lines for prevention of transmission of blood-borne infections.