MemBright: A Family of Fluorescent Membrane Probes for Advanced Cellular Imaging and Neuroscience

Abstract

The proper staining of the plasma membrane (PM) is critical in bioimaging as it delimits the cell. Herein, we developed MemBright: a family of six cyanine-based fluorescent turn-on PM probes that emit from orange to near-infrared when reaching the PM, and enable homogeneous and selective PM staining with excellent contrast in mono and two-photon microscopy. These probes are compatible with long-term live cell imaging and immunostaining. Moreover, MemBright label neurons in a brighter manner than surrounding cells allowing identification of neurons in acute brain tissue section and neuromuscularjunctions without any use of transfection or transgenic animals. At last, MemBright were used in super-resolution imaging to unravel the dendritic spines' neck. 3D multicolor dSTORM in combination with immunostaining revealed en-passant synapse displaying endogenous glutamate receptors clustered at the axonal-dendritic contact site. MemBright probes thus constitute a universal toolkit for cell biology and neuroscience biomembrane imaging with a variety of microscopy techniques.

Endothelial cell‐derived extracellular vesicles alter vascular smooth muscle cell phenotype through high‐mobility group box proteins

“…Lipilight dyes by Membright were used to label cells and EVs. Lipilights contain two amphiphilic groups of zwitterions and alkyl chains which directly and stably insert into bilayer lipid membranes [26]. For direct labelling experiments, EC EV preparations were mixed with 200 nM Lipilight (560 nm) for 1 h at room temperature in the dark.…”

Peering into tunneling nanotubes—The path forward

“…Given the current scarcity of a TNT‐specific biomarker, the prevailing method in TNT labeling is the staining of the entire plasma membrane with fluorescently conjugated proteins which bind glycolipids and glycoproteins, such as WGA (Abounit et al , 2015), FM1‐43 (McCoy‐Simandle et al , 2016), and MemBright (Collot et al , 2019). Alternatively, overexpressing proteins associated with the plasma membrane, such as H‐Ras, CAAX, and Lyn also serve a similar purpose (Caneparo et al , 2011; Rainy et al , 2013; Hanna et al , 2019).…”

Ral GTPases promote breast cancer metastasis by controlling biogenesis and organ targeting of exosomes

“…For fluorescent labeling, isolated EVs were incubated with MemBright-Cy3 or Cy5 (Collot et al, 2018) at 200nM (zebrafish) and 500nM (mice) (final concentration) in PBS for 30 minutes at room temperature in the dark. Labeled EVs were then rinsed in 15ml of PBS, centrifuged at 100,000g with a SW28 rotor in a Beckman XL-70 centrifuge and pellets were resuspended in 50 μL PBS.…”