A digital plating platform for robust and versatile microbial detection and analysis

Traditional plate culturing remains the "gold standard" in microbiology labs, but it is hindered by labor-intensive workflows, prolonged incubation times, and limited single-cell resolution. labor-intensive, time-consuming, and resource-heavy. Herein, we propose a digital plating (DP) platform that integrates the principles of traditional plate culturing with cutting-edge digital bioassay technology, enabling rapid isolation, quantification, and phenotypic characterization of microorganisms. The DP consists of a high-density picoliter microwell array chip covered with a replaceable agar sheet. In the DP platform, bacterial suspension is partitioned into a high-density picoliter microwell array chip via a self-pumping mechanism and incubated after covering with a specific nutrient- or/and chemical-laden agar sheet. Thanks to the replaceability of the agar cover "plate", the DP allows flexible change of the microenvironment in picowells for culturing or screening microbes, which significantly extends its application range. Meanwhile, the DP platform enables precise bacterial quantification within hours, significantly faster than conventional plate culturing (e.g., in the case of Escherichia coli, 6-7 h for the DP vs. 16-24 h for traditional methods). The platform's versatility is demonstrated through (i) single-cell isolation from mixed microbial communities, (ii) selective enrichment using differential media, (iii) rapid antibiotic susceptibility testing (< 6 h), and (iv) quantitative assessment of microbial interactions. By combining digital quantification with agar-based workflows, the DP platform bridges the gap between high-throughput microfluidics and practical laboratory routines, offering a scalable, cost-effective solution for clinical diagnostics, environmental microbiology, and synthetic biology.