von der Emde, H. | Search bioRxiv

bioRxiv2023

MINSTED tracking of single biomolecules

We show that MINSTED localization, a method whereby the position of a fluorophore is identified with precisely controlled beams of a STED microscope, tracks fluorophores and hence labeled biomolecules with nanometer/millisecond spatio-temporal precision. By updating the position for each detected photon, MINSTED recognizes fluorophore steps of 16 nm within < 250 microseconds using about 13 photons. The power of MINSTED tracking is demonstrated by quantifying side-steps of the motor protein kinesin-1 walking on microtubules and switching protofilaments.

biophysics↗

bioRxiv2022

MINSTED nanoscopy enters the Angstrom localization range

We report all-optical, room-temperature localization of fluorophores with precision in the [A]ngstrom range. These precisions are attained in a STED microscope, by encircling the fluorophore with the low-intensity edge of the STED donut beam, while constantly increasing the absolute donut power. Individual fluorophores bound to a DNA strand are localized with{sigma} = 4.7 [A], corresponding to a fraction of the fluorophore size, with only 2,000 detected photons. MINSTED fluorescence nanoscopy with single-digit nanometer resolution is exemplified by imaging nuclear pore complexes and the distribution of nuclear lamin in mammalian cells labeled by transient DNA hybridization. Since our experiments yield a localization precision{sigma} = 2.3 [A], estimated for 10,000 detected photons, we anticipate that MINSTED will open up entirely new areas of application in the study of macromolecular complexes in cells.

biophysics↗