Cellular membrane chromatography (CMC) has rapidly gained popularity in interaction research based on a variety of interaction sites existing on membrane receptors. Nevertheless, the conventional technique always needs a large amount of cells for preparing columns. Micro-CMC (mCMC) is a desirable choice to reduce membrane consumption by integrating cell membranes into capillary-based microsystems. Innovative coating techniques have been investigated to develop stable mCMC with improved cell membrane capacity. Since CMC possesses a complicated preparation procedure, state-of-the-art whole cell-immobilized capillaries have attracted tremendous interest nowadays. Bacterial cell walls are generally negatively charged, facilitating the attachment of a bacterial cell to the inner surface of functionalized capillaries. Bacteria-involved microscale systems provide a suitable platform for antimicrobial research. Integrating bacteria into capillary-based and microchip-based systems can potentially yield more efficient microdevices because of bacteria-specific properties.

Attributing to its favorable separation capacity, the microscale system presents a promising potential in biological assembly analysis. As the basic structural units of living organisms, cells present heterogeneity in terms of phenotype and genotype. Therefore, single-cell metabolome assay is essential for exploring life mysteries. Cancer is considered one of the most threatening diseases to human beings. Currently, the rapidly expanding advancement of microscale systems offers novel opportunities for cancer diagnosis and treatment. Novel efforts have been focused on investigating various capillary-based and microchip-based systems for cancer cell analysis. Exploring effective capillary electrophoresis (CE) techniques for nucleic acid analysis is another essential domain in microscale separation science. Pathogenic microorganisms such as bacteria and viruses are the culprits that cause numerous human diseases. Bacteria DNA is a desirable molecule for providing biological information and analyzing bacteria with low concentrations. To enhance the detection sensitivity of microscale systems, increasing attention has been paid to the combination of microchip CE with different nucleic acid-based circle amplification strategies, including polymerase chain reaction (PCR), rolling circle amplification (RCA), hybridization chain reaction (HCR), and catalysed hairpin assembly (CHA), loop-mediated isothermal amplification (LAMP), and probe-lengthening amplification (PLA).

The aim of this Special Issue is to collate original research articles providing valuable inputs in microscale systems design for microbiological research. Submissions focusing on the development of novel capillary- and microchip-based systems and the improvement of current technologies are also encouraged. Imaging technologies from super-resolution to atomic force microscopy for studying the micro and nanoscale properties are included as well. Moreover, we hope that this Special Issue increases our understanding of microorganisms. Review articles discussing the state of the art are also welcome.

Potential topics include but are not limited to the following:

• Bacteria-involved microscale systems for interaction research
• Microchip-based systems for bacteria analysis
• Capillary-based systems for bacteria analysis
• Microchip-based systems for cell analysis
• Capillary-based systems for cell analysis
• Bacteria-involved microscale systems for antimicrobial research
• Bacteria-involved microscale systems for pharmaceutical analysis