Quarterly Journal of Microscopical Science, Vol s3-105, 139-162, Copyright © 1964 by Company of Biologists

On Bridging the Gap in Cytology Between the Light and Electron Microscopes by Some Combined Observations on Snail Neurones

¹ Electron Microscopy Laboratory, Virus Research Unit, Medical Research Council Laboratories, Carshalton, Surrey

Discrepancies between observations made with the light microscope only, and with the electron microscope only, can be clarified by using both instruments to study exactly the same section of the same object. A simple technique for doing this is outlined. Direct, phase-contrast, ‘anoptral’ phase-contrast, dark-ground, interference, and ultra-violet microscopy can all be used. When applied to snail neurones this technique of combined observations reveals intracellular organelles which have not previously been differentiated. These organelles are positively identified by criteria appropriate to each instrument. By combined observations it is possible to see the ‘Golgi apparatus’ in preparations stained only with Nile blue, by direct microscopy. Data obtained by combined observations are considered in relation to the previous literature. Unequivocal cross-correlations between the light and the electron microscope go a long way towards explaining past difficulties.