Bridget Hanser


I am a Biophysics graduate student in the laboratory of John Sedat which is part of the Structural Biology Group in the Dept. of Biochemistry and Biophysics at UCSF - UC San Francisco .


Projects

New Approaches for Correction of Biologically-Induced Aberrations In Widefield Fluorescence Imaging

Microscopy is used for the structural analysis of biological samples ranging from multicellular tissue to subcellular structures. Fluorescence microscopy, in particular, has numerous uses, such as the examination of cellular activities, localization of particular cellular components, and, increasingly, quantitative measurement. However, properties of the sample and the sample setup can lead to significant degradations of image quality, which limit the resolution of collected data. This is especially true for live samples, which must survive any culture condition alterations aimed to improve imaging properties. Since fluorescent tools for imaging live samples are constantly improving and being used, solving this problem is becoming increasingly important.

How do non-ideal conditions affect imaging? A mismatch of immersion medium with a homogenous sample will cause depth-dependent loss of contrast and resolution, focal position shifts between varying wavelengths and axial focus errors for all forms of fluorescence microscopy. These effects result in observed aberrations in the expected point spread function(PSF -- the blurring of a point source recorded by a detector over a specified focal range) for conventional microscopy and depth-dependent attenuation for confocal microscopy, as well. Additionally, properties of the sample, such as refractive index differences between different subregions within a cell will also affect imaging quality.

The goal of my project is to develop means to quantify and computationally compensate for these imaging aberrations for conventional (widefield) microscopy during the deconvolution process, where data collection lens' PSF is used to remove the out-of-focus information. I will take a series of steps to move from the current, spatially invariant deconvolution to a process which will allow measured sample properties to direct a spatially variant deconvolution. I also hope to develop evaluation tools and a modeling system with which one can determine the best method for accomplishing this end.

Other Research stuff...

For Simplex help (image alignment program I've been futzing with), look at:

 Spiffy SIMPLEX help for all ages .

Someday I'll get more stuff on here... (REALLY!!!)


Personal Webpage

Click HERE to see my lame personal page!




file last futzed with: June 23, 1999.