A comparison of six methods of extracting elastin residue from hamster lungs.

Elastin was extracted from homogenized lungs by six commonly used methods. Results were expressed as micrograms of elastin per milligrams of fat-free dry weight of lung tissue. Relative purity of extracted elastin residue was assessed by amino acid analysis. Relative intactness of extracted residue was assessed by a degradation index utilizing a combination of N-terminal analysis and amino acid analysis. Results indicate that of the six methods compared, none is ideal in terms of purity and intactness of the resultant product extracted from lung tissue. In general, harsher methods produce a pure but degraded product, whereas milder methods produce a product that is intact but contaminated. In conclusion, most currently available methods of extracting elastin from tissues appear poorly suited to extracting it from lung tissue. However, the Starcher method yields a product as pure as that obtained by the Lansing procedure and one almost as intact as that obtained by the least degradative methods.