Using microfluidic impedance cytometry to identify the life stages of C. elegans nematodes

This paper presents a method to identify the life stages of Caenorhabditis elegans (C. elegans) by means of electrical impedance spectroscopy (EIS). A simple microfluidic chip, composed of a straight microchannel and a pair of coplanar electrodes was designed to form a microfluidic impedance cytometry. The electrodes were used to perform the impedance measurement of C. elegans nematodes when worms were flowing through the channel. Electrical signals and concurrent videos were recorded and analyzed to investigate the relationship between the impedance amplitude and the worm length. The result demonstrated that the length of nematodes is linearly correlated to the cubic root of EIS signal amplitude. Therefore, the life stages of C. elegans can be identified through this microfluidic impedance cytometry.