What is the difference between SMLM, PALM, STORM and PAINT?

Single molecule localization microscopy (SMLM) consists in inducing the fluorescence emission of only a subset of molecules at a given time in order to localize each of them individually. By repeating this process, you can accumulate enough localizations to reconstruct a final super-resolved image.

STORM, PALM and PAINT are all based on SMLM principle. The only difference is the way to induce the stochastic emission of the fluorophores:

• In STORM (Stochastic Optical Reconstruction Microscopy), fluorescent organic dyes (cyanines, rhodamines, …etc.) together with a specific imaging buffer (Abbelight’s buffer) are used to allow blinking of the fluorescent molecules;
• In PALM (Photo-activated Localization Microscopy), photoactivatable, photoconvertible or photoswitchable proteins are used (ex: PA-GFP, PA-mCherry, mEOS, mMAPLE, …etc.);
• In PAINT (Point Accumulation for Imaging in Nanoscale Topography), reversibly-binding fluorescent probes are used (ex: Nile Red).