Detection of single quantum dots in model organisms with sheet illumination microscopy

Area of Science:

• Biophysics
• Microscopy
• Developmental Biology

Background:

• Single-molecule detection and tracking are crucial for understanding biomolecular interactions within the microenvironment.
• Existing microscopy techniques face limitations in speed, penetration depth, and applicability to living systems for single-molecule studies.

Purpose of the Study:

• To develop and demonstrate a novel selective plane illumination microscopy (SPIM) setup capable of single-molecule detection and tracking in living organisms.
• To achieve fast imaging speeds and significant optical penetration depth for observing dynamic biological processes at the single-molecule level.

Main Methods:

• Implementation of a selective plane illumination microscopy (SPIM) system optimized for single-molecule sensitivity.
• Utilizing fluorescent nanoparticles (nanocrystals and quantum dots) as single-molecule probes.
• Imaging and tracking of single quantum dots in developing zebrafish embryos and single nanocrystals in Drosophila larvae.

Main Results:

• Demonstrated fast single-molecule imaging and tracking capabilities in living organisms using the new SPIM setup.
• Achieved optical penetration beyond 300 micrometers in biological samples.
• Observed the transition of single quantum dot motion from flow to confined states during early zebrafish development.

Conclusions:

• The developed SPIM technique enables unprecedented fast single-molecule imaging and tracking in living systems.
• This advancement provides a powerful new tool for studying biomolecular dynamics and cellular processes in vivo.
• The observed quantum dot dynamics offer insights into early developmental processes in zebrafish.