Electron spin resonance absorption of tissue constituents.

Abstract
The ESR spectra at g = 2 of the structural and soluble proteins of mouse liver were investigated separately. The structural materials have signals an order of magnitude stronger. Radicals with important similarities to those occurring in natural tissue can be induced by treating casein with methylglyoxal or crotonaldehyde. The structural proteins of cancer give little or no signal. The color of the proteins and their ESR signal seem closely related.