Notch spatial filtering of image artifacts for structured illumination microscopy of cell-based assays

Improvement of structured illumination microscopy (SIM) to remove grid pattern noise was investigated by applying notch spatial filters in the Fourier domain. We have acquired wide-field and SIM images of pollen grains and evaluated multiple reconstruction schemes on a quantitative basis. The results suggest that grid pattern noise can be reduced substantially to be smaller than that of standard SIM by more than 18 times, at the expense of little overhead in the reconstruction time. Also, if notch spatial filters are used in combination with subtractive reconstruction, the overall image quality can be enhanced by almost ten times, compared to standard SIM.