Studies on the quantitative autoradiography. I. Radioluminography for quantitative autoradiography of 14C

Evidence is presented to elucidate whether or not quantitative analysis of autoradiographs can be obtained with a 14C-labelled compound by the use of a new type of radiosensor called Imaging plate (IP). Our results showed that a linear relationship between relative intensity of PSL-BG and radioactivity of a given area was obtained. The linearity was maintained in a relatively wide range from 10(1) to 10(5) dpm of radioactivity. About 100 times higher sensitivity of the IP than any commercially available X-ray film was demonstrated for not only 14C-radioactive standard sources but also experimentally obtained 14C-radioactive spots developed on a TLC plate. Results also showed a linear relationship between relative intensity and radioactivity of the specimens in a very wide range from 10(1) to 10(5) dpm/mg after exposure for 7d. Furthermore, the relationship between PSL-BG and relative exposure (radioactivity x exposure time) was linear when PSL-BG was from 10(1) to 10(5). In addition to the above properties, a combination of IP and BAS2000, a computerized image display system, was able to completely erase the background prior to use.