Application of Stellar Photometry To The Analysis of Microarray Images

Mahyar Sabripour1, Christopher I. Amos2, Kevin Coombes, Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center;, Department of Epidemiology, The University of Texas M. D. Anderson Cancer Center

The development of DNA microarray technology gives researchers unique opportunities to identify genetic factors that may be critical for the prevention and treatment of cancer. A critical step in the analysis of microarray data is the quantification of spots on the array platform. Insufficient attention has been given to the precision and accuracy of spot intensities. The spot intensities directly influence the results and interpretation of statistical analyses. Improvements in quantifying spots can directly impact the identification of genes critical to the development and progression of cancer. This is especially true with the quantification of faint signals with respect to background noise. We utilize a stellar photometric model, the Moffat function, to analyze cDNA membrane microarray images. The Moffat function, a point spread function (PSF), has traditionally been used in the astronomical community for describing the intensity distribution of stars. In the current setting, we fit the Moffat function to cDNA spots on the array and obtain intensity values. The flexibility of the Moffat function allows the variability seen in cDNA spot size and shape to be taken into account when quantifying spots. We present results showing the effectiveness of the Moffat function in quantifying spots and compare these results with other standard image processing techniques.