Indicate whether each of the following descriptions better applies to SIM (S), STED (T), or STORM/PALM (P) superresolution techniques. Your answer would be a four-letter string composed of letters S, T, and P only, e.g. PPTS.
( ) It switches on and off individual fluorophores at random over time to accurately determine their position.
( ) It creates a moiré pattern from the interference of the illuminating pattern and the sample features.
( ) It doubles the resolution of conventional fluorescence microscopy.
( ) It limits excitation to the fluorophores that are located at the center of the focal point by using a doughnut-shaped beam in addition to the excitation beam.

Question

Indicate whether each of the following descriptions better applies to SIM (S), STED (T), or STORM/PALM (P) superresolution techniques. Your answer would be a four-letter string composed of letters S, T, and P only, e.g. PPTS.
( )	It switches on and off individual fluorophores at random over time to accurately determine their position.
( )	It creates a moiré pattern from the interference of the illuminating pattern and the sample features.
( )	It doubles the resolution of conventional fluorescence microscopy.
( )	It limits excitation to the fluorophores that are located at the center of the focal point by using a doughnut-shaped beam in addition to the excitation beam.

Quizplus · Accepted Answer

Different superresolution fluorescence techniques overcome diffraction-limited resolution in different ways. For example, through illumination by a grid, structured illumination microscopy (SIM) can improve the resolution by about a factor of two. Stimulated emission depletion microscopy (STED) uses a bright torus-shaped lased beam to switch the fluorescent molecules off at the periphery of the point spread function. Single-molecule localization methods such as photoactivated localization microscopy (PALM) or stochastic optical reconstruction microscopy (STORM) use lasers to sequentially switch on a sparse subset of fluorescent molecules in a specimen.

Indicate Whether Each of the Following Descriptions Better Applies to SIM