How to quantitatively measure, assess and correct the fluorescence crosstalk in the wide-field microscopy

Abstract

During the multi-color fluorescence imaging, a fluorophore can be detected in the non-corresponding channel due to the broad spectra of the fluorophore and filters, resulting in the artefact called the crosstalk (crossover or bleed-through). Unfortunately, the fluorescence crosstalk is ubiquitous for the conventional fluorescence microscopy. Significant crosstalk can distort the image and lead to incorrect interpretation. Here, we introduce a simple quantitative metric, the crosstalk factor, to measure the crosstalk effect of a fluorophore on a channel in the wide-field fluorescence microscopy. We describe a cell biologist friendly protocol which should be easily implemented by cell biologists using commonly available image processing software such as ImageJ.