This video demonstrates the use of fluorescence fluctuation spectroscopy to detect the interaction among cell surface proteins at cell-cell contacts. By expressing the transmembrane adhesion receptor of interest labeled with a fluorescent protein and mixing two different cell populations harboring two spectrally separated fluorescent labels, the trans-interaction between the receptors of two neighboring cells with different-colored fluorescence is assessed via cross-correlation in the fluctuations of fluorescence intensity.
Protocol
1. Sample Preparation: Cell-Cell Mixing Assay NOTE: The following protocol describes the mixing procedure for adherent cells. It may be modified for cells cultured in suspension. Seed an appropriate number of cells on a 6-well plate, e.g., 800,000 HEK 293T cells (counted with a Neubauer counting chamber), a day before transfection. The number can be modified depending on the time between seeding and transfection and adjusted for other cell types. To perfor…
Representative Results
Figure 1. Experimental workflow and schematic representation of scanning fluorescence cross-correlation spectroscopy and cross-correlation number and brightness analysis at cell-cell contacts. (A) Scheme of sample preparation: Two cell populations transfected with the protein of interest (e.g., APLP1) fused to two spectrally distinct fluorescent proteins (e.g., mEYFP and mCardina…
Açıklamalar
The authors have nothing to disclose.
Materials
DMEM growth medium
PAN-Biotech
P04-01548
DPBS w/o: Ca2+ and Mg2+
PAN-Biotech
P04-36500
DPBS w: Ca2+ and Mg2+
PAN-Biotech
P04-35500
Trypsin EDTA
PAN-Biotech
P10-023100
TurboFect Transfection Reagent
Thermo Fisher Scientific
R0531
HEK 293T cells
DSMZ
ACC 635
Alexa Fluor 488 NHS Ester
Thermo Fisher Scientific
A20000
Rhodamine B
Sigma-Aldrich
83689-1G
Plasmid DNA
Addgene
NA
See Dunsing et. al., MBoC 2017, for a detailed description of all plasmids