Deterioration of storage phosphor screens with use

Abstract More than 1000 laboratories worldwide use phosphorimager systems for radioisotopic gel and blot quantification. This method is extraordinary sensitive and has a wide dynamic range, and it is therefore often preferred to conventional film‐based analysis. We checked the accuracy of our storage phosphor screen by exposing the same 32 P‐labelled blot in different positions on the same screen. The first exposure took place at the top of the screen, an area used more often; the second exposure at a relatively little‐used area of the screen. As the screens are said to last indefinitely, regardless of how often they are used, we did not expect a difference in the results. In fact, we found a significant impact of the position of the gel on the results. The position that was used more often gave inaccurate results; in contrast, the unused area of the screen gave data that were confirmed by X‐ray film autoradiography. We conclude that, contrary to described properties, a deterioration of the phosphor screens takes place with repeated use. To avoid obtaining invalid data, we recommend frequent checks of the screens. Copyright © 2002 John Wiley & Sons, Ltd.