High-throughput sorting of eggs for synchronization of C. elegans in a microfluidic spiral chip

In this study, we report the use of a high-throughput microfluidic spiral chip to screen out eggs from a mixed age nematode population, which can subsequently be cultured to a desired developmental stage. For the sorting of a mixture containing three different developmental stages, eggs, L1 and L4, we utilized a microfluidic spiral chip with a trapezoidal channel to obtain a sorting efficiency of above 97% and a sample purity (SP) of above 80% for eggs at different flow rates up to 10 mL min^-1. The result demonstrated a cost-effective, simple, and highly efficient method for synchronizing C. elegans at a high throughput (∼4200 organisms per min at 6 mL min^-1), while eliminating challenges such as clogging and non-reusability of membrane-based filtration. Due to its simplicity, our method can be easily adopted in the C. elegans research community.