TABLE 2.

Error propagation analysis for the E-FRET formula

Variable or parameter	ΔEapp [%] (Absolute error of Eapp in response to 10% input error)
	Eapp = 0%	Eapp = 10%	Eapp = 30%
IDD	1.7	2.2	2.8
IDA	2.7	3.0	3.3
IAA	0.89	0.72	0.43
a	0.89	0.72	0.43
d	1.9	1.5	0.92
G	0	0.82	2.0
Actual per-pixel error*	2.4	2.5	2.6
Actual pixel noise†	1.4	1.2	1.1

Error propagation analysis was performed on Eq. 12 and Eq. 13 by introducing a 10% disturbance into each variable (I_DD, I_DA, I_AA) or parameter (a, d, G) of the formulae. The resulting deviation of E_app is shown for three levels of E_app as indicated. The unit of error is the percent of energy transfer. The starting parameters were a = 0.077, d = 0.647, G = 3.50, I_DD = 750, I_AA = 3000, I_DA = 716.1 (for E_app = 0%), I_DA = 1008 (for E_app = 10%), and I_DA = 1845 (for E_app = 30%). Intensities are expressed in the relative camera response units. These values represent typical readings during actual experiments except for the input errors.

^*The actual per-pixel accumulated error of E_app was calculated based on 2 × 2 binning and input errors specified in the Methods for the dual-camera system.

^†The actual pixel-to-pixel noise is contributed only by the variables (I_DD, I_DA, I_AA).