Optotracing using Amytracker

Amytracker are optotracers with structure-dependent photo-physical properties. All Amytracker variants are designed to bind to the Congo red binding pocket on the amyloid fibril and require a theoretical minimum of eight in-register parallel-β-strands for binding. Therefore, Amytracker reliably labels amyloids derived from a variety of amyloidogenic proteins or peptides from different species. Due to their structure-dependent photo-physical properties, the Amytracker variants are only fluorescent when binding to a target and different targets can produce a difference in the molecules fluorescence spectrum. To investigate different targets, we recommend collecting excitation and emission spectra with excitation and emission parameters summarised in the table below. Reference spectra for all Amytracker variants can be accessed here.

Table: Amytracker spectral properties with maximum excitation (Ex_max) and emission (Em_max) when bound and recommended range for acquisition of excitation- and emission spectra as well as recommended filter sets for microscopy.

	Exmax	Emmax	Excitation spectrum (detect at Emmax)	Emission spectrum (excite at Exmax)	Recommended filter-sets
Amytracker 480	420 nm	480 nm	300 - 450 nm	450 - 800 nm	DAPI
Amytracker 520	460 nm	520 nm	300 - 490 nm	490 - 800 nm	FITC, GFP
Amytracker 540	480 nm	540 nm	300 - 510 nm	510 - 800 nm	FITC, GFP, YFP
Amytracker 630	520 nm	630 nm	300 - 600 nm	550 - 800 nm	PI, Cy3, TxRed, mCherry, Cy3.5
Amytracker 680	530 nm	680 nm	300 - 650 nm	660 - 800 nm	PI, mCherry, Cy3.5