Species ELISA Type I ELISA Type II
Bovine 1002 2012
Chick 1001 2011
Human 1005 2015
Monkey - 2017
Mouse 1006 2016
Porcine 1003 2013
Rat 1004 2014

ELISA Grade Type I Collagen

Product Quantity Catalog #
ELISA Grade Bovine Type I Collagen 0.5 mg/ml x 1 ml 1002
ELISA Grade Chick Type I Collagen 0.5 mg/ml x 1 ml 1001
ELISA Grade Human Type I Collagen 0.5 mg/ml x 1 ml 1005
ELISA Grade Mouse Type I Collagen 0.5 mg/ml x 1 ml 1006
ELISA Grade Porcine Type I Collagen 0.5 mg/ml x 1 ml 1003
ELISA Grade Rat Type I Collagen 0.5 mg/ml x 1 ml 1004

ELISA Grade Type II Collagen

Product Quantity Catalog #
ELISA Grade Bovine Type II Collagen 0.5 mg/ml x 1 ml 2012
ELISA Grade Chick Type II Collagen 0.5 mg/ml x 1 ml 2011
ELISA Grade Human Type II Collagen 0.5 mg/ml x 1 ml 2015
ELISA Grade Monkey Type II Collagen 0.5 mg/ml x 1 ml 2017
ELISA Grade Mouse Type II Collagen 0.5 mg/ml x 1 ml 2016
ELISA Grade Porcine Type II Collagen 0.5 mg/ml x 1 ml 2013
ELISA Grade Rat Type II Collagen 0.5 mg/ml x 1 ml 2014

ELISA Grade Type III Collagen

Product Quantity Catalog #
ELISA Grade Porcine Type III Collagen 0.5 mg/ml x 1 ml 1093

Individual collagen molecules (monomeric collagen) consist of three alpha chains in a triple helix conformation. As an individual ages, monomeric collagen molecules become cross-linked by oxidization and form polymeric collagen. Collagen purified from animal tissues is usually a mixture of monomeric and polymeric collagen. When using collagen as an antigen for indirect ELISA systems to detect anti-collagen antibodies, polymeric collagen can pose a significant issue. 

Due to its cross-linkages, polymeric collagen will form multiple layers of collagen when used to coat ELISA plate surfaces. This collagen multi-layer provides multiple epitopes for anti-collagen antibody binding and can lead to overestimation of anti-collagen antibody levels in serum and plasma samples (Figure 1 below). Variations in the degree of cross-linking between polymeric collagen preparations can also lead to inconsistent ELISA results. On the other hand, monomeric collagen is ideal for use as an ELISA antigen because it will only form a monolayer of collagen on ELISA plate surfaces, and therefore provide more accurate quantification of anti-collagen antibodies in samples.  

Chondrex, Inc.’s ELISA Grade Collagen is specifically prepared for use as an ELISA antigen for assays designed to quantify anti-collagen antibodies. Our ELISA Grade Collagen is native form (undenatured), monomeric collagen that has been pepsin-solubilized from various tissues. Each vial of collagen comes with 0.5 mg of collagen (enough to coat ten 96-well plates). Additionally, our 10X Collagen Dilution Buffer (Cat # 9003) is provided with each vial of ELISA Grade Collagen. This buffer is designed to prevent collagen fibril formation when coating plates. For more information, please see our recommended protocol for coating ELISA plates with ELSIA Grade Collagen.

In order to accommodate the variety of collagen studies available, Chondrex, Inc. offers different grades of collagen such as immunization grade, cell culture grade, ELISA grade, T-cell assay grade, and collagen CB fragments. If you need help deciding which grade of collagen is right for your study, please see our Understanding Chondrex, Inc.’s “Grades” of Purified Collagen article or contact us. For more information distinguishing between Type I and Type II collagen, please see our Type I & Type II Collagen: Structure Influences Staining Patterns article or contact us.

Figure 1: A. Side view of an ELISA plate well coated with monomeric collagen, forming a monolayer of individual collagen molecules. B. Side view of an ELISA plate well coated with polymeric (cross-linked) collagen, creating a multi-layer of collagen proteins. This multi-layer provides multiple epitopes for anti-collagen antibodies in serum/plasma samples to bind, which can lead to an overestimation of antibody levels. Using monomeric collagen as an ELISA antigen will produce more reliable and reproducible assay results. 
*Collagen shown as double helix for simplicity.