Figure 4.

TEM micrographs and investigations of the ZCSE2 bacteriophage. (a) Image showing a group of three negatively stained phages acquired by parallel illumination in TEM mode using the Philips CM12 microscope. (b) Bright-field scanning transmission electron microscopy (BF-STEM) image acquired by the probe-corrected Titan microscope for an isolated ZCSE2 bacteriophage showing the main morphological components: long head, collar, tail tube, tail fibers, baseplate, and a spike. (c) STEM-high annular angle dark field (HAADF) image acquired simultaneously with the BF-STEM image in STEM mode with the double-correction of the spherical aberration in both probe and imaging plans. (d) High-resolution TEM image of the same phage acquired with single-correction in the imaging plan only in TEM mode using a US1000FTXP CCD camera. (e) TEM image showing a fully contracted tail sheath with the core visible, where the contracted tail diameter (13.1 nm) was less than the average (14.9 ± 2.7 nm) of the uncontracted tail diameter, as expected, due to the squeezing of the helical tail tube. (f) Illustration figure showing the main dimensions of the ZCSE2 bacteriophage, as measured from the TEM images acquired during screening the sample.