Controlled rotation of biological microscopic objects using optical line tweezers.
Controlled, continuous rotation of cells or intracellular objects was achieved using optical tweezers with an elliptic beam profile (line tweezers), which was generated by placing a cylindrical lens in the path of the trapping beam. By rotating the cylindrical lens, rotation of the elliptic trapping beam and hence of the object trapped therein was achieved. Compared to previously reported techniques for rotation of microscopic objects, this approach is much simpler, gives better utilization of available laser power and also allows much easier control of the trap beam profile. We have used this approach for rotation of biological objects varying in size from 2 to 40 microm. At 25 mW trapping beam power at the object plane E. coli bacteria could be rotated at speeds approaching 10 Hz and an intracellular object (presumably a calcium oxalate crystal) trapped inside Elodea densa plant cell could be rotated with speeds of up to 4 Hz. To our knowledge, this is the first report for rotation of an intracellular object.
Biomedical Applications Section, Center for Advanced Technology, Indore-452013, India.
Raktim
R
Dasgupta
Samarendra K
SK
Mohanty
Pradeep K
PK
Gupta
D002465:Cell Movement / Q000528:radiation effects*; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004912:Erythrocytes / Q000166:cytology / Q000528:radiation effects*; D004926:Escherichia coli / Q000166:cytology / Q000528:radiation effects*; D006801:Humans; D007834:Lasers; D019684:Magnoliopsida / Q000166:cytology / Q000528:radiation effects; D008846:Micromanipulation / Q000295:instrumentation* / Q000379:methods; D055095:Optics and Photonics / Q000295:instrumentation*; D010812:Physical Stimulation / Q000295:instrumentation* / Q000379:methods; D012399:Rotation; D013347:Subcellular Fractions / Q000528:radiation effects / Q000648:ultrastructure