The negative staining of "difficult" bacteria like Arthrobacter globiformis for electron microscopy

A method is suggested for the negative staining of "difficult" bacteria like Arthrobacter globiformis for electron microscopy when the usual procedures do not give satisfactory results. It involves glutaraldehyde fixation, and thorough washing and drying of the cell suspension on a grid sitting on a bed of plain agar, followed by a rapid flushing with 2% phosphotungstic acid.