Phagocytosis assays with different pH-sensitive fluorescent particles and various readouts

Phagocytosis is a fundamental mechanism of innate immunity and its impairment is associated with severe chronic diseases, for example, chronic obstructive pulmonary disease. Investigating phagocytosis requires flexible tools and assay conditions, such as different fluorescent particle types, detection colors and readouts. We comprehensively evaluated and optimized phagocytosis assays using particles labeled with fluorescent pH-sensitive pHrodo® dyes, facilitating the specific detection of phagocytosed particles. Beads, bacterial and yeast particles labeled with pHrodo red and green were tested for their uptake by THP-1 cells and primary human macrophages by flow cytometry and high-content imaging. Whereas the latter allowed kinetic phagocytosis measurement, the former demonstrated the feasibility of using cell sorting for periods of up to 6 h, enabling downstream applications such as pooled genetic screens.

Ultrabright dye-loaded spherical polyelectrolyte brushes and their fundamental structure-fluorescence tuning principles

A novel ultrabright fluorescent particle based on dye-loaded polyelectrolyte brushes is successfully established and the structure-fluorescence tuning principles are revealed.

Application of nanodiamonds in Cu(ii)-based rhodamine B probes for NO detection and cell imaging

A nanodiamond-conjugated rhodamine fluorescent sensor for Cu(ii) which could then be developed as an excellent NO selective fluorescent particle.