[Electron spin resonance study of melanin in paraffin-imbedded ocular melanoma specimens]

The Electron Spin Resonance (ESP) spectrum of ocular melanomas embedded in paraffin was studied. In the g approximately 2.003 range of the spectrum a mark of a free radical was detected. The correlation between the amplitude of the latter and the number of melanin granules in sections was studied. Considering the positive correlation revealed, authors believe, that ESR spectroscopy is a suitable tool for detecting melanin in paraffin embedded specimens. As an effect of oxidation or reduction melanin turns pale, however this phenomenon is not in tight connection with the decrease of the amplitude of the free-radical-mark. Very seldom different types of spectrum (peroxide, cupric ion) may appear, so it is reasonable to study large number of specimens.