Amino acid analysis of elastin hydrolysates using a lithium citrate gradient: quantification of elastin from whole lung.

A method to quantitate the elastin content in lungs is described. Desmosine and isodesmosine, the cross-linking amino acids unique to elastin, were measured directly from acid hydrolysates of hamster and human lungs by amino acid analysis. A Durrum D-500 (Dionex) amino acid analyzer, with a modified lithium citrate buffer gradient was used. Results compared favorably with those obtained by gravimetric and microenzymatic techniques, and the method described could be used for the quantification of elastin in biopsy specimens