So-called neuronal ceroid-lipofuscinosis. Histochemical study with evidence of extractibility of the stored material.

Histochemical study of so-called neuronal ceroid-lipofuscinoses (NCL) showed that the stored material is extractable in the unfixed state especially with alkalized or acidified chloroform-methanol mixtures when compared with other solvents. The extractability was strongly reduced or almost abolished by fixation with formaldehyde. Identical results were obtained with the type one storage material (see Elleder, 1977) in all late infantile cases and in a juvenile case studied, in which, contrary to the infantile form, the stored material displayed a significantly higher degree of extractability. As far as the extractability of the type two storage material is concerned insufficient data have been accumulated, but it seems that it does not differ significantly from the first one. In the control group of lipopigments ceroid was found to be much more extractable under identical conditions than matured lipofuscin which was almost entirely resistant to all extraction procedures. The significance of the results is discussed.