Phosphorescent zinc sulfide is a nonradioactive alternative for marking autoradiograms

Phosphorescent zinc sulfide is a nonradioactive alternative for making orientation and identification markings on autoradiograms. Measurements with a luminometer show that light emission is linear with respect to ZnS concentration. A minimum activation time of 5 s has been determined, using an incandescent lamp as a light source. Emission decay kinetics show light emissions reached background levels within minutes, depending on the ZnS concentration. This time period is sufficient for X-ray films to be permanently marked. Because of its efficiency and nontoxicity, this autoradiogram marker could be extremely useful in many protocols, including high-throughput radioactive DNA sequencing. This nonradioactive marker will also be useful in protocols utilizing nonradioactive detection systems, such as those calling for biotinylated and chemiluminescent probes.