Which of the following methods does NOT use electrons for imaging?
Scanning Probe Microscopy encompasses techniques like AFM and STM that map surfaces using physical probe interaction rather than radiation. AFM measures force between cantilever tip and sample, while STM measures tunneling current, both independent of electron beams. In contrast, TEM, SEM, and cryo-EM all utilize accelerated electrons focused by electromagnetic lenses to generate images, requiring vacuum and electron optics. SPM operates in air, liquid, or vacuum and senses topography at atomic resolution via mechanical forces, providing complementary information about surface properties, elas
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.