Cells are physically contacting with each other. Direct and precise quantification of forces at cell–cell junctions is still challenging. Herein, we have developed a DNA-based ratiometric fluorescent probe, termed DNAMeter,...

Infections caused by bacterial biofilms are challenging to diagnose due to the complexity of both the bacteria and the heterogeneous biofilm matrix. We report here a robust polymer-based sensor array that uses selective interactions between polymer sensor elements and the biofilm matrix to identify bacteria species. In this array, appropriate choice of fluorophore enabled excimer formation and inter-polymer FRET, generating six output channels from three polymers. Selective multivalent interactions of these polymers with the biofilm matrices caused differential changes in fluorescent patterns, providing a species-based signature of the biofilm. The real-world potential of the platform was further validated through identification of mixed-species bacterial biofilms and discrimination of biofilms in a mammalian cell-biofilm co-culture wound model.

Mechanical interactions between cells have been shown to play critical roles in regulating cell signaling and communications.H owever,t he precise measurement of intercellular forces is still quite challenging,e specially considering the complex environment at cell-cell junctions.Inthis study,we report af luorescence lifetime-based approach to image and quantify intercellular molecular tensions.U sing this method, tensile forces among multiple ligand-receptor pairs can be measured simultaneously.W efirst validated our approach and developed lifetime measurement-based DNAtension probes to image E-cadherin-mediated tension on epithelial cells.T hese probes were then further applied to quantify the correlations between E-cadherin and N-cadherin tensions during an epithelial-mesenchymal transition process.T he modular design of these probes can potentially be used to study the mechanical features of various physiological and pathological processes.

Phenotyping macrophage activation states using an array-based sensor. FRET complex assembly selectively interacts with the macrophage surface, generating a fingerprint for each polarization state that is further used to identify the activation state.