Double isotope autoradiography

A double emulsion autoradiographic technique is described which provides a high resolution method of detecting 14C and 3H simultaneously in a single tissue section. Two emulsions are used which differ in their sensitivity to beta radiation. One emulsion is applied to the top of the section, the other to the bottom. The top emulsion is sensitive to 3H beta particles and insensitive to 14C. Specificity for 14C is accomplished by using a celloidin film which separates the second 14C-sensitive emulsion from close contact with the section. Both emulsions are exposed and processed together. The final autoradiograph is viewed on a single slide. The 14C emulsion can be seen by focusing on the lower side of the section and the 3H emulsion by focusing on the upper side.