No abstract

Biomolecular phase separation is currently emerging in both the medical and life science fields. Meanwhile, the application of liquid–liquid phase separation has been extended to many fields including drug discovery, fibrous material fabrication, 3D printing, and polymer design. Although more than 8600 proteins and other synthetic macromolecules are capable of phase separation as recently reported, there is still a lack of a high-throughput approach to quantitatively characterize its phase behaviors. To meet this requirement, here, we proposed fast and high-resolution acquisition of biomolecular phase diagrams using microfluidic chips. Using this platform, we demonstrated the phase behavior of polyU/RRASLRRASLRRASL in a quantitative manner. Up to 1750 concentration conditions can be generated in 140 min. The detection limitation of our device to capture the saturation concentration for phase separation is about 5 times lower than that of the traditional turbidity method. Thus, our results provide a basis for the rapid acquisition of phase diagrams with high-throughput and pave the way for its wide application.

Summary Current method for obtaining microbial colonies still relies on traditional dilution and spreading plate (DSP) procedures, which is labor‐intensive, skill‐dependent, low‐throughput and inevitably causing dilution‐to‐extinction of rare microorganisms. Herein, we proposed a novel ultrasonic spraying inoculation (USI) method that disperses microbial suspensions into millions of aerosols containing single cells, which lately be deposited freely on a gel plate to achieve high‐throughput culturing of colonies. Compared with DSP, USI significantly increased both distributing uniformity and throughput of the colonies on agar plates, improving the minimal colony‐forming abundance of rare Escherichia coli mixed in a lake sample from 1% to 0.01%. Applying this novel USI to a lake sample, 16 cellulose‐degrading colonies were screened out among 4766 colonies on an enlarged 150‐mm‐diameter LB plate. Meanwhile, they could only be occasionally observed when using commonly used DSP procedures. 16S rRNA sequencing further showed that USI increased colony‐forming species from 11 (by DSP) to 23, including seven completely undetectable microorganisms in DSP‐reared communities. In addition to avoidance of dilution‐to‐extinction, operation‐friendly USI efficiently inoculated microbial samples on the agar plate in a high‐throughput and single‐cell form, which eliminated masking or out‐competition from other species in associated groups, thereby improving rare species cultivability.