Measuring the size of human cells is hard, or requires fancy equipment most people don’t have. Our tool makes it much easier. Our preprint is available here on bioRxiv http://disq.us/t/3cykkni
We express a fluorescent protein from a constitutive promoter so that its amount is proportional to cell size, then measure total fluorescence by flow cytometry or widefield microscopy. We show that these measurements correlate well with those from other established methods including flow cytometry, protein-binding dye, nuclear volume, and dry mass. Crucially, we also show that our fluorescence measurements are more robust and less dependent on image segmentation than is the commonly-used measurement of nuclear volume. Moreover, our straightforward technique, requiring only a wide field fluorescence microscope, does not require equipment unavailable to most cell biology laboratories and is compatible with commonly used live cell imaging methods. Finally, use of two colors allows estimation of the concentration (ratio of your favorite protein to the size reporter) of the second fluorescently tagged protein. Thus, our reporter can be used to facilitate concentration measurement using simple wide field instrumentation available in most cell biology labs.
Nice work Daniel!