Practice question

Tracking intracellular distribution of specific proteins relies on labeling with antibodies conjugated to fluorophores emitting distinct colors. Fluorescence microscopy selectively detects these conjugates using wavelength-specific excitation and barrier filters against dark background, providing molecular specificity unattainable with refractive-index based methods. Fixed and permeabilized cells stained for cytoskeletal components, transcription factors or organelle markers reveal spatial patterns indicating functional states. DIC and bright field show morphology only, while transmission electron microscopy requires heavy metal stains lacking multiplex color capacity needed for simultaneous mapping of multiple proteins within single cells.