In phosphor imaging, a storage phosphor screen captures the energy from the radioactive material. The storage screen contains a thin layer of crystals that absorb and store energy emitted by radioactive material. The storage screen is exposed to a radioactive sample, such as a blot or tissue section.
After the exposure, the screen is imaged by scanning with a laser (Figure 1). The laser converts the stored energy to visible light which can be captured using a digital imaging system. The emitted light is proportional to the amount of radioactivity present in the original sample, making phosphor imaging excellent for quantitative comparisons. The figures below demonstrate the linearity and wide dynamic range possible with phosphor imaging.