Deconvolution of wide-field microscope images of the parasite Toxoplasma gondii expressing YFP tubulin (Swedlow et al. 2002). (Left) One focal plane near the plasma membrane from a 3D stack of raw images of YFP fluorescence in several living parasites. (Middle) The same focal plane after processing of the 3D stack by constrained iterative deconvolution. Microtubules are clearly visible as bright striations. (Right) A plot of the change in intensity along the dashed lines in the raw data and in the data after deconvolution. Deconvolution greatly improved the SNR by restoring the out-of-focus light to its proper location. (Specimen kindly provided by Dr. Ke Hu, Indiana University, Bloomington. Images and deconvolution courtesy of Paul Goodwin, Applied Precision Inc.)