Stuck in the Loop?
A New Way to Study the Amplification Loop

New Factor P Assays

We are happy to announce the launch of a quantitative Factor P assay and the first commercially available functional Factor P assay. Together, these assays let you explore the delicate balance of the complement system in a whole new way. 

What is Factor P?

Factor P, also referred to as Properdin, has an important role in the amplification loop of the complement system. Upon binding to C3bBb, it acts as a stabilizer, extending the half-life of C3bBb significantly. 

In addition, it inhibits the factor H-mediated cleavage of C3b by factor I, thereby increasing C3b formation and positively regulating the complement cascade response.

As an up-regulator of the complement system, properdin is of interest to pharmaceutical companies looking for therapeutic targets, as well as to academic groups studying the amplification loop.

Two Assays – One Antibody

We are happy to announce the launch of two new ELISA-based Factor P assays:

  • A quantitative Factor P assay
  • The first commercially available functional Factor P assay

These assays allow you to accurately measure the levels of properdin and determine its functionality. Moreover, since the assays use the same capture antibody, you can directly relate the properdin concentration and function in your samples.

In addition, the assays can easily be adapted to more in-depth studies, granting a closer look at the amplification loop.


Principle of the quantitative factor P assay

In the quantitative assay, the wells are coated with a capture antibody that binds to Factor P (FP) in the sample. An enzyme-conjugated detection antibody and a corresponding substrate are used to generate a signal corresponding to the properdin concentration in the sample.


properdin regular elisa


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Principle of the functional factor P assay

Factor P (FP) is bound by the same capture antibody in the functional assay as in the quantitative assay. A reference serum is then added. If the initial sample contains functional properdin, C3 from the reference will be cleaved to C3b. An enzyme-conjugated detection antibody is used to detect C3b in the well. 



Complementing our complement portfolio

The launch of these assays complements our wide range of biomarker assays and functional assays available for the complement system.

Contact us for more information

Would you like to learn more about our products or discuss your project with one of our complement experts?