Densitometry

Densitometry can be performed from both film and/or phosphor screens. Isotopically labeled sections will generate a gray scale image in proportion to the level of labeling. Along with tissue sections, a calibrated standard is included with each film or phosphor screen, if densitometry is planned. The standard has been previously calibrated to 3H or 35S. The film or phosphor screen is used along with the image analysis program MCID (Amersham, Inc look up details). The optical density of the standards are determined and a calibration curve is generated against known tissue levels. Gray scale or optical density values from any region of interest is compared to the gray scale value from the calibration curve and a tissue equivalent is obtained. Values can be obtained from small regions of interest in particular nuclei of the brain or from subregions of any organ. Densities can also be obtained for the entire organ. Differences in density between organs or between organs at different ages or under the influence of an experimental condition can be determined. Values from multiple conditions can be averaged and statistical analysis performed. The precision of this technique is very high and sample sizes of three to four may be adequate for statistical analysis.

Molecular Histology Center Environmental and Occupational Health Sciences Institute, 170 Frelinghuysen Road, Piscataway, NJ 08854 Phone: 732-445-3729 For additional information contact ekr@eohsi.rutgers.edu

Updated on Friday, June 03, 2005