Lumogallion (4-Chloro-3-(2,4-dihydroxyphenylazo)-2-hydroxybenzene-1-sulfonic acid) is an azo reagent used in the determination of metal ions, such as the research of V, Fe, and Al.

Instructions
a. Solution preparation: Dissolve lumogallion in DMSO or 0.1 M acetate buffer (pH 5.2) and prepare a 10mM storage solution for later use.
Note: The storage solution needs to be stored at -20℃ or -80℃. Please avoid repeated freezing and thawing. The diluted working solution should be prepared and used as soon as possible.
b. Operation steps:
1. Incubate the sample with 10 μM lumogallion in the dark for 60 min.
2. Wash the mixed sample twice with acetate buffer, 15 minutes each time.
3. Observe under a laser confocal microscope, with an excitation wavelength of 488 nm and an emission wavelength of 520 nm.