Counting autoradiography grains

Description of the Problem

Autoradiography is a useful technique for scientists who wish to probe the content of individual cells and of tissues. The autoradiography process enables scientists to attach silver grains to cells and tissues exhibiting certain properties. The number of grains attached to biological materials can be related to specific biological phenomena. Thus, by counting the grains attached to cells and tissues, scientists can extract a quantitative measure of specific chemical events. Unfortunately, the task of counting grains is extremely laborious and error-ridden. Compounding the effects of human fatigue, staining obscures individual grains, making it difficult to obtain accurate results. In addition, extraneous grains not attached to tissues of interest are often counted accidentally.

The Solution using OPTIMAS

Using OPTIMAS, researchers have developed several methods for quantifying autoradiography binding sites. OPTIMAS is used to count binding sites on individual cells. Images with poor contrast can be processed using a custom filter designed with OPTIMAS to identify the boundaries of individual cells. A special filter is then passed over the original image to identify autoradiography binding sites. Using a simple macro procedure, OPTIMAS steps sequentially through each cell and counts the grains that lay inside the cell boundary. The resulting data file provides an accurate record of numbers of cells and the number of binding sites attached to each cell.

In addition to automatically counting cells and binding sites, the macro procedure helps to reduce human error by guiding lab technicians systematically through the processes of lighting correction, cell counting, and measurement. The flexible image analysis tools with OPTIMAS permit the investigators to quickly customize image processing filters and macro procedure for each study.