You are a scientist studying the highly specific interactions of bacteriophages with their host cells when they first encounter the cell. Discuss what microscope(s) and preparation procedures you might use for this study

Question

What will be an ideal response?

Answer 1

A scanning electron microscope can produce three-dimensional images of the physical contact between bacteriophage and host, providing information on what portions of the bacteriophage are in contact with what structures of the cell. A mixture of bacterial cells and bacteriophages is dried onto the surface of the sample holder and coated with metal to prepare it for the scanning electron microscope. A transmission electron microscope may provide information about structures and interactions obscured by the intact bacteriophage. Samples are dried, embedded in plastic, sliced into thin (100 nm) sections, and stained with heavy metals (osmium, tungsten, etc.) to increase contrast.
Scanning tunneling or atomic force microscopy of separate preparations of bacteriophages and bacterial cells can provide details about the structures on each that interact when the bacteriophage is in contact with the surface of the cell. The preparation of specimens for atomic force microscopy is minimal, as the material does not need to be dried, sectioned, or stained.