https://3demmethods.i2pc.es/index.php?action=history&feed=atom&title=2009Sorzano_Sensitivity 2026-05-24T19:52:58Z Revision history for this page on the wiki MediaWiki 1.44.2 https://3demmethods.i2pc.es/index.php?title=2009Sorzano_Sensitivity&diff=1910&oldid=prev 2009-06-11T09:31:47Z

<p></p> <p><b>New page</b></p><div>== Citation ==<br /> <br /> Sorzano, C. O. S.; Otero, A.; Olmos, E. M. &amp; Carazo, J. M. Error analysis in the determination of the electron microscopical contrast transfer function parameters from experimental power spectra BMC Structural Biology, 2009, 9, 18<br /> <br /> == Abstract ==<br /> <br /> Background: The transmission electron microscope is used to acquire structural information of<br /> macromolecular complexes. However, as any other imaging device, it introduces optical<br /> aberrations that must be corrected if high-resolution structural information is to be obtained. The<br /> set of all aberrations are usually modeled in Fourier space by the so-called Contrast Transfer<br /> Function (CTF). Before correcting for the CTF, we must first estimate it from the electron<br /> micrographs. This is usually done by estimating a number of parameters specifying a theoretical<br /> model of the CTF. This estimation is performed by minimizing some error measure between the<br /> theoretical Power Spectrum Density (PSD) and the experimentally observed PSD. The high noise<br /> present in the micrographs, the possible local minima of the error function for estimating the CTF<br /> parameters, and the cross-talking between CTF parameters may cause errors in the estimated CTF<br /> parameters.<br /> <br /> Results: In this paper, we explore the effect of these estimation errors on the theoretical CTF.<br /> For the CTF model proposed in [1] we show which are the most sensitive CTF parameters as well<br /> as the most sensitive background parameters. Moreover, we provide a methodology to reveal the<br /> internal structure of the CTF model (which parameters influence in which parameters) and to<br /> estimate the accuracy of each model parameter. Finally, we explore the effect of the variability in<br /> the detection of the CTF for CTF phase and amplitude correction.<br /> <br /> Conclusion: We show that the estimation errors for the CTF detection methodology proposed<br /> in [1] does not show a significant deterioration of the CTF correction capabilities of subsequent<br /> algorithms. All together, the methodology described in this paper constitutes a powerful tool for<br /> the quantitative analysis of CTF models that can be applied to other models different from the one<br /> analyzed here.<br /> <br /> == Keywords ==<br /> <br /> CTF estimation, error analysis, error sensitivity<br /> <br /> == Links ==<br /> <br /> Article http://www.biomedcentral.com/content/pdf/1472-6807-9-18.pdf<br /> <br /> == Related software ==<br /> <br /> == Related methods ==<br /> <br /> == Comments ==</div>

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