Improvement of the silver staining method for bacterial flagella

Flagella staining is a common method used in microbial research to identify and mark morphological features of bacteria. We improved the Blendon staining method by adding two steps to the usual procedure, viz. “preparation of a pre-atomized microscope slide” and “stretching flagella in situ”. The staining effects were then comparatively studied for this new, improved method on Bacillus subtilis, under four different culture conditions: 1) liquid culture medium, 2) aqueous solution at the bottom of slant medium, 3) solid culture medium adding water for stretching after culture, and 4) semi-solid culture medium adding water for stretching after culture. The results revealed that after the addition of these two steps to the usual procedure, the order of the staining effects for the four culture conditions from best to worst was as follows: semi-solid culture medium > solid culture medium > aqueous solution at the bottom of slant medium > liquid culture medium. Hence, the semi-solid culture medium brought about the best staining effect, with flagella stretching freely and not entangled with each other, while the liquid culture medium had the worst staining, owing to the serious background interference. This improved method is simple, low cost, and worthy of promotion.