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The rapid development of scientific CMOS (sCMOS) technology has greatly advanced optical microscopy for biomedical research with superior sensitivity, resolution, field-of-view, and frame rates. However, for sCMOS sensors, the parallel charge-voltage conversion and different responsivity at each pixel induces extra readout and pattern noise compared to charge-coupled devices (CCD) and electron-multiplying CCD (EM-CCD) sensors. This can produce artifacts, deteriorate imaging capability, and hinder quantification of fluorescent signals, thereby compromising strategies to reduce photo-damage to live samples. Here, we propose a content-adaptive algorithm for the automatic correction of sCMOS-related noise (ACsN) for fluorescence microscopy. ACsN combines camera physics and layered sparse filtering to significantly reduce the most relevant noise sources in a sCMOS sensor while preserving the fine details of the signal. The method improves the camera performance, enabling fast, low-light and quantitative optical microscopy with video-rate denoising for a broad range of imaging conditions and modalities.

Desmosomes are cell–cell junctions that provide mechanical integrity to epithelial and cardiac tissues. Desmosomes have two distinct adhesive states, calcium-dependent and hyperadhesive, which balance tissue plasticity and strength. A highly ordered array of cadherins in the adhesive interface is hypothesized to drive hyperadhesion, but how desmosome structure confers adhesive state is still elusive. We employed fluorescence polarization microscopy to show that cadherin order is not required for hyperadhesion induced by pharmacologic and genetic approaches. FRAP experiments in cells treated with the PKCα inhibitor Gö6976 revealed that cadherins, plakoglobin, and desmoplakin have significantly reduced exchange in and out of hyperadhesive desmosomes. To test whether this was a result of enhanced keratin association, we used the desmoplakin mutant S2849G, which conferred reduced protein exchange. We propose that inside-out regulation of protein exchange modulates adhesive function, whereby proteins are “locked in” to hyperadhesive desmosomes while protein exchange confers plasticity on calcium-dependent desmosomes, thereby providing rapid control of adhesion.