Super-resolution microscopy has enabled valuable insights into the subcellular , mechanistic details of many different biological processes across a wide range of cell types. Fluorescence polarization spectroscopy tools have also enabled important insights into cellular processes through identifying orientational changes of biological molecules typically at an ensemble level. Here, we combine these two biophysical methodologies in a single home-made instrument to enable the simultaneous detection of orthogonal fluorescence polarization signals from single fluorescent protein molecules used as common reporters on the localization on biomolecules in cellular processes , whose spatial location can be pinpointed to a super-resolved precision better than the diffraction-limited optical resolution  . In this small innovation we have adapted a millisecond timescale "Slimfield" microscope used for single-molecule detection to enable spitting of the fluorescence polarization emissions into two separate imaging channels for s- and p- polarization signals that are imaged onto separate halves of the same high sensitivity back-illuminated CMOS camera detector. We applied this fluorescence polarization super-resolved imaging modality to a range of test fluorescent samples relevant to the study of biological processes, including purified monomeric green fluorescent protein (mGFP) . Our findings are largely qualitative but demonstrate promise in showing how fluorescence polarization and Slimfield-mediated super-resolved localization microscopy can be combined on the same sample to enable new biological insights .
Super-resolution microscopy has catalyzed valuable insights into the sub-cellular , mechanistic details of many different biological processes across a wide range of cell types. Fluorescence polarization spectroscopy tools have also enabled important insights into cellular processes through identifying orientational changes of biological molecules typically at an ensemble level. Here, we combine these two biophysical methodologies in a single home-made instrument to enable the simultaneous detection of orthogonal fluorescence polarization signals from single fluorescent protein molecules used as common reporters on the localization of proteins in cellular processes . These enable measurement of spatial location to a super-resolved precision better than the diffraction-limited optical resolution , as well as estimation of molecular stoichiometry based on the brightness of individual fluorophores . In this innovation we have adapted a millisecond timescale microscope used for single-molecule detection to enable splitting of fluorescence polarization emissions into two separate imaging channels for s- and p- polarization signals , which are imaged onto separate halves of the same high sensitivity back-illuminated CMOS camera detector. We applied this fluorescence polarization super-resolved imaging modality to a range of test fluorescent samples relevant to the study of biological processes, including purified monomeric green fluorescent protein , single combed DNA molecules, and protein assemblies and complexes from live Escherichia coli and Saccharomyces cerevisiae cells . Our findings are qualitative but demonstrate promise in showing how fluorescence polarization and super-resolved localization microscopy can be combined on the same sample to enable simultaneous measurements of polarization and stoichiometry of tracked molecular complexes, as well as the translational diffusion coefficient .
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enabled
catalyzed
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subcellular
sub-cellular
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on biomolecules
of proteins
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, whose spatial location can be pinpointed
. These enable measurement of spatial location
A
, as well as estimation of molecular stoichiometry based on the brightness of individual fluorophores
D
small
D
"Slimfield"
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spitting of the
splitting of
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that
, which
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(mGFP)
, single combed DNA molecules, and protein assemblies and complexes from live Escherichia coli and Saccharomyces cerevisiae cells
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largely
D
Slimfield-mediated
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new biological insights
simultaneous measurements of polarization and stoichiometry of tracked molecular complexes, as well as the translational diffusion coefficient