Table 2.

Properties of selected AFPs and CPs used in PA imaging.

Protein	Absa	ε at peakb	ε at 650 nmc	Φd	Ref.e
EGFP	488	53	0.2	0.6	[69]
DsRed	558	52	1.2	0.68	[70]
E2-Crimson NFf, g	583	NDh	NDh	NDh	[67]
mCherry	587	72	0.1	0.22	[71]
Ultramarinei	587	64	2.3	0.001	[72]
dUltramarine2g	587	82	~3	<0.0001	[73]
tdUltramarine2j, g	587	203	~7.3	<0.0001	[73]
mKate	588	45	0.2	0.33	[74]
AQ143k	595	90	9.7	0.04	[62]
aeCP597i	597	110	12	NDh	[62]
mRaspberry	598	86	1.9	0.15	[75]
mNeptune	600	67	2.2	0.2	[76]
E2-Crimson	605	59	4.6	0.12	[77]
cjBluei	610	67	3.6	<0.0001	[78]
cjBlue2g	603	57	<3.1	<0.0001	[73]
TagRFP657	611	34	4.6	0.1	[79]

^aAbsorbance maximum in nm

^bExtinction coefficient at peak in units of mM^-1cm^-1determined by alkali denaturation

^cExtinction coefficient at 650 nm in units of mM^-1cm^-1 calculated as a product of ε at peak and excitation or absorption efficiency at 650 nm. Excitation or absorption efficiency is defined as the ratio of excitation or absorption at a given wavelength to that at peak.

^dFluorescence quantum yield

^eSource of data

^fE2-Crimson's non-fluorescent variant

^gNaturally occurring chromoproteins

^hNot determined

ⁱEngineered chromoproteins

^jA tandem fusion of two copies of dUltramarine2

^kaeCP597's bright variant