Fluorescence micrograph of an assay for cell fusion. Pig kidney cells were labeled with two different dyes (red, green) and mixed together to grow on a plastic dish. The cells were then infected with a strain of pseudo-rabies virus with a fluorescently labeled virus component (a capsid protein fused to cyan fluorescent protein, rendered as blue in this image). If spread of infection caused cell fusion, yellow-orange cells would be expected as the red dyes mix with the green ones.
Image Source: Princeton Art of Science, 2009 Competition.
