Microscopic observation of Sudan Black B staining to monitor lipid production by microbes

In experimental investigations on the improvement of yields and productivities of lipids from oleaginous micro‐organisms in fermenters, a bottleneck is the speedy determination of the extent of accumulation of the intracellular lipids. The use of Sudan Black B for staining and direct observation under the microscope enables the rapid observation of the qualitative status of lipid production in the cells. A change in the colour of the stain from dark to light blue observed during the course of the fermentation has been found to be related to a change in the extent of unsaturation of the lipids.