For sensitive densitometric quantification, combine the DensitoMetrics package with a Sapphire equipped with the green channel.
In contrast to sending white light through an X-ray film or a colorimetrically stained gel, with DensitoMetrics light travels through the sample twice, as shown in the figures below. The densitometry plate emits fluorescent light when illuminated by the laser. The plate is placed over the sample, and the laser light travels through the sample towards the plate. Any fluorescence emitted by the plate passes back through the sample to the detector. The sample can block some of the laser light from reaching the screen, and also block some of the resulting fluorescent light from reaching the detector. Any reduction in the amount of light is proportional to the amount of material in the band on the gel or film.