Single-cell sorting of marine plankton based on micro-optical tweezers

Abstract

Marine plankton are micro and diverse, and most of them are still non-cultivable. So single-cell analysis, focused on the study of diversity and heterogeneity of their cells, has become a hot issue in marine microbiology research, which relies on sound single-cell preparation technology for upstream operations. By combining micro-optical tweezers technology with microfluidic droplet wrapping technology, we developed a fluorescence microscopic optical tweezers system for plankton sorting. Our system consists of a micro-optical tweezers module, a fluorescence module, an imaging module and a sorting module. Using this system, we conduct single-cell observation, monitoring, capture manipulation, separation and extraction of microplankton in seawater samples. The specific process is as follows: 1. Prepare samples, including grading filtration and enrichment of seawater sampled in Qingdao offshore. 2. Observe and select the target single-cell with a specific sorting chip on the microscopic optical tweezers single-cell sorting system. And perform visualized microdroplet single-cell sorting through optical tweezers capture manipulation. 3. Take out the target living single-cell after forming microdroplets. Using our experimental system, we are able to provide precise technical support for downstream experiments including single-cell culture, sequencing and monoclonality. In addition, our method has the advantages of flexible operation, intact cells and visualization as "what you see is what you get". Meanwhile, it has a 100% single-cell acquisition rate while maintaining the high viability of the sorted cell.