OPTICAL MANIPULATIONS OF C.ELEGANS BIO ORGANISMS IN MICROFLUIDIC CHIPS FOR BEHAVIOURAL STUDIES

Abstract

Caenorhabditis elegans is a 1mm genetically modifiable roundworm. Here, we study a strain of modified optogenetic C.elegans, more sensitive to blue light, and analyse its reaction to 473nm, 532nm, 650nm and 1064nm lasers at different powers for behavioural experiments inside a bio-compatible PDMS microfluidic chip. Three generations of chips were created to replicate the worms natural environment. They have been fabricated by adapting a UV soft lithography procedure. Most notably, the optogenetic strain had an instantaneous aversive reaction after exposure to low power blue beams. Both modified and non-modified strains reacted to the heat produced by infrared laser, as confirmed with a thermo-sensitive dye. Finally, we built a complex optical set-up, containing a spatial light modulator diffracting the blue laser beam into various patterns projected onto the chips, allowing to control worms motion. Coupled with infrared laser punishment, this could allow biologists to perform numerous behavioural experiments on C.elegans.