fluorescein yellow CH lithium salt is a water-soluble dye with an excitation/emission peak of 428 /536 nm. This is the most commonly used tool for studying neuronal morphology because it contains a carbohydrazide (CH) group that allows it to be covalently linked to surrounding biomolecules during aldehyde fixation. The lithium salt form of Lucifer Yellow CH is commonly used for microinjection because its solubility is higher than the potassium and ammonium salt forms of Lucifer Yellow CH.