Atomic force microscopy analysis of bacteriophages [Phi]KZ and T4

Bacteriophage [Phi]KZ was investigated by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The well-known phage T4 was used as a reference sample. Reproducible contact mode AFM images of native and partially disintegrated particles of bacteriophage [Phi]KZ in air were obtained. It was demonstrated that the heads of [Phi]KZ and T4 phages were compressed differently and depended on adsorption onto highly ordered pyrolytic graphite and mica. We have established a procedure to partially disintegrate the viral particles after which the internal protein body, which is a helical structure with a cylinder-like form, was easily observable inside the bacteriophage [Phi]KZ head.