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.