Complement system Classical Pathway WIESLAB®

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The increased awareness and interest in the complement system has augmented the need for a simple and objective method to assess the function of complement activity. Objective quantification of the activity of the classical pathway is valuable in a number of different clinical situations. In order to meet the needs, the assay has been redesigned to further optimize objective quantification. A separate calibrator curve is now included in the assay procedure to facilitate the quantitative assessment. The amount of complement activation can be expressed either in a qualitative way relative the value of a positive control (as previously) or in a semi-quantitative way using a calibrator curve derived from a separate lyophilized activity control.

With the Euro Diagnostica complement assay solution (previously known as WIELISA) a complete picture of the complement function is provided.

Complement System Website

Read more about the complement system, details related to the diagnostics, treatment and multiple applications on our dedicated Complement System Website!


Product code
Break apart microtitration strips (12x8) 96 wells
Qualitative / Semi-quantitative
Refer / Calibrator curve
Incubation time
60+30+30 min
Detection system
405 nm
CE marked. Available in US only for research use, not for IVD use

Intended use

The Wieslab® Complement system Classical pathway is an enzyme immunoassay for the qualitative and/or semi-quantitative determination of functional classical complement pathway in human serum. The analysis should be performed by trained laboratory professionals.


This product is also available as research use only. Product code: COMPL CP310 RUO

For complete product description, claims and use, please refer to the Instructions For Use. Contact your local representative for availability in your country.


The complement system plays an essential role in chronic, autoimmune and infectious disease. There are three pathways of complement activation, namely the classical, the alternative and the MBL pathway.

Impaired complement activity causes humans to become susceptible to repetitive fulminant or severe infections and may contribute to development of autoimmune disease. Inappropriate activation of complement contributes to chronic inflammation and tissue injury.

Technical information

The Wieslab® Complement assay combines principles of the hemolytic assay for complement activation with the use of labeled antibodies specific for neoantigen produced as a result of complement activation. The amount of neoantigen generated is proportional to the functional activity of complement pathways.

In the Complement Screen CP kit, the wells of the microtitre strips are coated with specific activators of the classical pathway. This in combination with sample dilution buffer composition and patient serum dilution level ensure that only the Classical pathway is activated.

During the incubation of the diluted patient serum in the wells, complement is activated by the specific coating. The wells are then washed and the amount of C5b-9 complex formed on the plate surface is detected with a specific alkaline phosphatase labelled antibody to the C5b-9 neoantigen formed during MAC (Membrane Attack Complex) formation.

After a further washing step, detection of specific antibodies is obtained by incubation with alkaline phosphatase substrate solution. The amount of complement activation correlates with the colour intensity and is measured in terms of absorbance (optical density (OD)).

The amount of complement activation can be expressed either in a qualitative way relative the value of a positive control or in a semi-quantitative way using a calibrator curve derived from a separate lyophilized activity control.

Kit components and storage of reagents

- One frame with blue coloured break-apart wells (12x8) coated with human IgM, sealed in a foil pack with a desiccation sachet.

- 2 x 35 mL Diluent CP (Dil CP), labelled blue.

- 13 mL conjugate containing alkaline phosphatase-labelled antibodies to C5b-9 (blue colour).

- 13 mL Substrate solution ready to use.

- 30 mL wash solution 30x concentrated.

- 0,2 mL negative control (NC) containing human serum. (to be  diluted as for a patient serum sample).

- Lyophilized positive control (PC) containing freezed dried human serum, to be reconstituted in 0.2 mL distilled water, see “Reconstitution of positive control”, in the IFU.

- Lyophilized activity control (AC) for semi-quantitative application, containing freezed dried human serum (different origin than PC), see “Reconstitution of activity control” under procedure for semi-quantitative application in the IFU.

All reagents in the kit are ready to use except wash solution and controls. The reagents should be stored at 2-8° C except the positive control and the activity control. The positive control and the activity control should be stored at -20° C upon arrival. The reconstituted positive control and activity control should be stored at –70° C and may be thawed once.