ELISA Grade Collagen
ELISA Grade Type I Collagen
|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
|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
|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.