Work Item
ASTM WK69051

New Test Method for Assessing the Activation of the Complement System in Human Plasma Through Quantification of iC3b Concentration by ELISA,

1. Scope

The purpose of this assay is to determine complement activation by nanoparticles . Nanoparticles which may absorb within the assay range of the Enzyme Linked Immunosorbent Assay (ELISA) should be treated with caution due to interference. Inhibition/enhancement controls should always be included.


Nanoparticles, Enzyme, Immunosorbent, ELISA, complement, iC3b, plasma


The complement (C) system is a major contributor to innate immunity and is composed of more than 30 proteins. Three cascades (classical, lectin and alternative) may be activated by differing triggers resulting in the generation of complement component 3 (C3). In turn, particularly in the alternative pathway, C3 may further generate C3a and C3b. C3a acts as an anaphylotoxin that promotes inflammatory processes where C3b can be further cleaved to generate inactive C3b (iC3b) which has opsonic properties. Nanoparticles, and nanoparticulate surfaces, are known to activate the C system. Determination of C activation, ex vivo, by nanoparticles may provide information as to their biocompatibility and possible CARPAgenicity. This test method describe a protocol for the determination of C activation, in human plasma, by Enzyme Linked Immunosorbent Assay (ELISA) measurement of iC3b concentrations.

The title and scope are in draft form and are under development within this ASTM Committee.


Developed by Subcommittee: E56.08

Committee: E56

Staff Manager: Frank McConnell

Work Item Status

Date Initiated: 07-11-2019

Technical Contact: Julian Leakey

Item: 000