Statistical significance tests for autoradiographic data.

The purpose of this paper is to develop statistical methods that take radiation spread into account in analyzing data from different autoradiographic experiments. The method uses the probability circle analysis of Salpeter and McHenry (1973) to obtain the probable source of each radioactive emission and the circle and point counting method of Williams (1969) to estimate the relative area occupied by each cellular site. Two levels of analysis are presented. The first level of analysis is concerned with estimating relative activities and standard errors for cellular items that are larger than the probability circle. The second level of analysis involves estimating relative activities and standard errors for cellular sites that are smaller than the probability circle and are therefore observed in circles containing another item such as cytoplasmic matrix. Two different tests of hypotheses are discussed. The first null hypothesis is that the radioactivity is randomly distributed among the cellular sites. The second null hypothesis is that there is no difference between two different treatments in the relative activities for a given site.