Scanning tunneling microscopy of bacterial flagella

Scanning tunneling microscopy (STM) images have been obtained for three different types of uncoated helical flagella of bacteria, salmonella typhimurium SJW1103: intact flagella, sonicated flagella, and disassembled flagella (i.e., flagellin). Glycerol has been added to the desalinated sample solutions to prevent the aggregation of the sample in the solution, and to adhere to the samples onto the graphite surface. Freeze drying has been used to prevent the aggregation of the sample in the drying process. The molecular arrangement observed by STM is similar to that of the reported structure for straight flagella determined by x‐ray diffraction.