Study Of Microfluidic Chip For Caenorhabditis Elegans Based On Droplet Manipulation

Microfluidic chip is a microdevice that is capable of accomplishing chemical orbiology functions through manipulating picoliter-nanoliter fluids or droplets in μm-scalestructures. Microfluidic chip can be divided into two categories: continuous flow chipand droplets chip. Our laboratory has developed two new methods: magnetic repulsionmanipulation and positive gravity manipulation. In this thesis, we developed these twomethods and applied them to researching C. elegans on the chip.C. elegans is a common used multicellular model organism. It has been widelyemployed in chemistry, biology and environment. There have already been manyresearches of C. elegans on the chip. However, these works still had some defects, andin the thesis we developed two new microfluidic chips for worms.The first one was for short-term observation of worms on the chip based onmagnetic repulsion manipulation. The chip employed magnetic repulsion to controllabletrap, merge and release droplets. We trapped droplets containing a worm in each andmerged with previous trapped droplets which contained drug or toxin. Using this device,we studied the influence of Shuanglongfang on heat shock reaction of C. elegans andthe damage of Hg(II) on the swimming capability of the worms.The other device was applied to long-term culture of worms. The chip usedwater/oil or water/air interface on one side of the chamber and a20μm exit on the otherto confine worms. It also contained a champ structure to reversibly immobilize worms.In order to maintain a continuous aqueous phase in hydrophobic PDMS channels, wesuccessfully modified part of the channel. By moving the water/oil or water air interfaceby gravity-control system, we trapped, released and immobilized worms as well asrefreshed the medium. Thus we cultured and observed worms inside of the device for alifespan, and studied the correlation between growth, swimming ability and lifespan ofC. elegans. The results could be used to predict the lifespan of worms. Compare toexisting works, this device was simple, easy to fabricate and capable of releasing wormsand it had some values on longitudinal research of worms.