= FRET spectral overlap
{c}
{title2=$J$}
<FRET spectral overlap> quantifies overlap between the <FRET donor>'s emission and the <FRET acceptor>'s absorption as functions of <wavelength> $\lambda$. With normalized donor emission $f_D$ and acceptor molar absorption coefficient $\varepsilon_A$, one convention is
$$
\int_0^\infty f_D(\lambda)\,d\lambda=1,\qquad J=\int_0^\infty f_D(\lambda)\varepsilon_A(\lambda)\lambda^4\,d\lambda.
$$
Matching two emission colors is insufficient: the receiving absorption matters.<Advanced Fluorescence Microscopy Techniques—FRAP, FLIP, FLAP, FRET and FLIM by Hellen C. Ishikawa-Ankerhold and others>[§3.1, equation 17 and Figure 19: normalized donor emission and acceptor absorption overlap]{ref}
Back to article page
