Native collagen can be evaluated using immunoassays with monoclonal antibodies (mAbs) against collagen. Most mAbs were developed by native collagen immunization. Denatured collagen is easy to be degraded by proteinase in our body, losing antigenicity.

We may need to know a ratio of native and denatured collagen in, especially, biomaterials, such as artificial cartridges.

For this purpose, the following method should work.

1. Analyze total collagen level using a hydroxyproline assay
2. Analyze native collagen level using a immunoassay (ELISA)
3. Subtract the total collagen by native collagen to obtain the levels of denatured collagen

Hydroxyproline assay is the almost specific assay to determine collagen. Collagen and elastin are proteins only containing hydroxyproline. The ratio is almost 1:13 (hydroxyproline: other amino acids)(1).

1. G. K. Reddy, G. Kesava Reddy, C. S. Enwemeka, A simplified method for the analysis of hydroxyproline in biological tissues. Clinical Biochemistry. 29 (1996), pp. 225–229.