Initiation of the complement system results in the formation of a multiprotein pore termed the membrane attack complex (MAC, C5b-C9). MAC pores accumulate on a cell surface and can result in cell lysis. The retinal pigment epithelium (RPE) is a single monolayer of pigmented epithelial cells located at the posterior poll of the eye that forms the outer blood retinal barrier. RPE cells are highly polarized with apical microvilli and basolateral contact with Bruch’s membrane. In order to obtain biologically relevant polarized RPE cultures in vitro, RPE cells are seeded onto the apical side of a transwell filter and cultured for 4 weeks in low serum media. MAC formation on RPE cells has been reported to be sub-lytic. MAC formation can be achieved in vitro by introduction of normal human

The molecular mechanisms of P-glycoprotein (P-gp; also known as MDR1 or ABCB1) have been mainly investigated using artificial membranes such as lipid-detergent mixed micelles, artificial lipid bilayers, and membrane vesicles derived from cultured cells. Although these in vitro experiments help illustrate details about the molecular mechanisms of P-gp, they do not reflect physiological membrane environments in terms of lateral pressure, curvature, constituent lipid species, etc. The protocol presented here includes a detailed guide for analyzing the conformational change of human P-gp in living HEK293 cells by using intramolecular fluorescence resonance energy transfer (FRET), in which excitation of the donor fluorophore is transferred to the acceptor without emission of a photon when two

Most bacteria in natural ecosystems form biofilms-a bacterial community, surrounded by a polymer matrix that consists mostly of exopolysaccharides, proteins, and nucleic acids. Extracellular RNA as a matrix component is involved in biofilm formation-the fact that was confirmed by direct detection of extracellular RNA in the biofilm matrix, and by an interruption of the biofilm's structure with RNases. Number of protocols describing isolation of RNA from biofilm matrix are limited and usually involve uncommon equipment and reagents. Here we describe simple method for extracellular RNA isolation from biofilm matrix using basic laboratory reagent and equipment. Key steps of the protocol include separation of matrix and bacterial cells with high ionic solution of NaCl, RNA precipitation with