Figure 8 Ratio measurement of 620 nm and 665 nm wavelengths. The long-lived signals, 620 nm emission from free (Eu) K and the 665 nm emission from the bound (Eu)K and XL665 pair, provide a method for correcting for color or turbity in the reaction.

doi:10.1201/9780203910696-56

Chapter

Figure 8 Ratio measurement of 620 nm and 665 nm wavelengths. The long-lived signals, 620 nm emission from free (Eu) K and the 665 nm emission from the bound (Eu)K and XL665 pair, provide a method for correcting for color or turbity in the reaction.

Chapter

ABSTRACT

Assay data can be presented in terms of the ratio of the 665/620 nm measurements, R, to correct for any interference from media or absorption of excitation or emission wavelengths by the media. ∆R is the change in ratio that occurs with respect to the blank or negative sample. It is used to express the specific signal in the assay. ∆F is an instrument-independent measurement that shows the signal-to-noise ratio of the assay [14]. Both measurements utilize the patented ratio method of detection, which eliminates interference from test compounds, or turbidity of test samples. Discovery can provide raw 665-nm counts, raw 620-nm counts, or ratios. This patented technique is unique to HTRF measurement and is proprietary to this detection technology.