Fluorescent dye/probe
Lucifer Yellow CH does not have a biological or pharmacological target. It is a fluorescent probe used for cell labeling and tracing. The dye is taken up by cells through pinocytosis and can be used to study cell-cell communication via gap junctions. It is also used for staining neurons and marking nerve cells.

Making the working solution of Lucifer Yellow CH (dilithium salt).
1. Preparation of stock solution
To make a 1 mg/mL stock solution of Lucifer Yellow CH (dilithium salt), dissolve 1 mg of Lucifer Yellow CH (dilithium salt) in 1 mL of DDH2O.
Note: After aliquots, the Lucifer Yellow CH (dilithium salt) storage solution should be kept in the dark at -20°C or -80°C.
2. Utilizing the pre-heated serum-free media or PBS, dilute the stock solution into 0.5–1% Lucifer Yellow CH (dilithium salt) working solution.
Note: Before using, please make sure that the concentration of the Lucifer Yellow CH (dilithium salt) working solution is appropriate for the current circumstances.

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Staining of cells
1. Preparation of cells
Suspension cells: Centrifuge cells to collect them, then add PBS and wash twice for five minutes each time.
Adherent cells: Add islet digested cells after discarding the culture medium. Centrifuge, remove supernatant, add PBS, and wash twice for five minutes each time.
2. Add 1 mL of the working solution for 5–30 minutes (Lucifer Yellow CH, dilithium salt).
3. Discard the supernatant after centrifuging at 400 g for three to four minutes at 4°C.
4. To wash the cells twice, five times apiece, add PBS.
5. Re-suspend the cells in 1 milliliter of PBS or serum-free water, and observe using a flow cytometer or fluorescence microscope.

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Note:
1. After aliquoting, the Lucifer Yellow CH (dilithium salt) storage solution should be kept out of the light at -20°C or -80°C. Frequent freezing and thawing should be avoided. It can be kept for one month at -20°C and six months at -80°C.
2. You may adjust the Lucifer Yellow CH (dilithium salt) working solution concentration according to your specific needs.
3. This product should not be used for clinical diagnosis or treatment, nor should it be included into food or medication. It is intended only for research use.
4. Please wear disposable gloves and a lab coat for your health and safety.
In vitro, Lucifer Yellow CH is used as a fluorescent tracer for labeling cells and visualizing cellular morphology. The dye is taken up by cells through pinocytosis and can be used to study gap-junction communication through dye transfer. It has been used to demonstrate electrical coupling between hamster oocytes and cumulus cells.

Contrasting observations exist which indicate that in plants the fluorescent dye lucifer yellow CH (LYCH) either can be used as a tracer for endocytosis or as a substrate for an anion transporter located at the vacuolar membrane. In addition, LYCH as a disulphonated substance may represent an analogue of sulphonated or sulfated natural compounds like some flavonoids. We performed uptake experiments with LYCH into isolated rye vacuoles and observed saturable (Km = 0.3-0.6 mM) vacuolar transport and accumulation of the dye against the concentration gradient only when MgATP was present. GTP and, to a low extent, UTP could substitute for ATP, while the non-hydrolysable ATP analogue AMP-PNP did not drive LYCH uptake. Vanadate and probenecid, the latter substance is known to inhibit organic anion transport at the liver canalicular membrane, both strongly decreased the vacuolar uptake of LYCH, while bafilomycin A1, a specific inhibitor of the vacuolar H+-ATPase, had no effect. Together with the fact that abolishment of the delta pH via CCCP had only a weak influence on LYCH accumulation, our results indicate that this compound is taken up into rye vacuoles by a directly energized process. Uptake of LYCH was strongly inhibited by other sulfated compounds including sulfobromophthalein and the flavones apigenin 7,4'-disulfate and luteolin 7,4'-disulfate arguing for the presence of a vacuolar transporter for structurally different sulphonated or sulfated compounds. Glucuronates like the rye-specific flavone luteolin 7-O-diglucuronide also strongly decreased uptake of the dye, whereas only a weak effect was observed in the presence of glutathione and a glutathione conjugate, suggesting that LYCH uptake is not mediated via the vacuolar glutathione conjugate pump [2].
In vivo, Lucifer Yellow CH has been used to demonstrate electrical coupling between hamster oocytes and cumulus cells during meiotic maturation. It is also used for staining neurons in vivo. The dye's fixability allows it to be used in histological studies.

Non-cellular assays for Lucifer Yellow CH are not applicable as it is a fluorescent dye rather than an enzyme inhibitor. The compound's fluorescence properties can be characterized by measuring its excitation/emission maxima of 430/540 nm. Its quantum yield and photostability can be assessed using fluorescence spectroscopy.

In vitro cellular experiments involve incubating cells or tissues with Lucifer Yellow CH. The dye is taken up by cells through pinocytosis or microinjection. Uptake and distribution of the dye are visualized by fluorescence microscopy or confocal microscopy. Gap-junction communication is assessed by measuring dye transfer between cells.

In vivo animal studies for Lucifer Yellow CH involve injecting the dye into tissues or animals to label neurons or study dye transfer. The dye can be fixed in tissue using aldehyde-containing fixatives. Labeled cells or neurons are visualized by fluorescence microscopy.

Lucifer Yellow CH is not a drug and does not have pharmacokinetic properties. It has a molecular weight of 457.25 g/mol and a molecular formula of C₁₃H₉Li₂N₅O₉S₂. The dye is highly water-soluble and has excitation/emission maxima of 430/540 nm.

Lucifer Yellow CH has low toxicity and is generally considered safe for use as a fluorescent tracer. The compound is for research purposes only and should be handled with appropriate safety precautions.

[1]. Stewart WW. Functional connections between cells as revealed by dye-coupling with a highly fluorescent naphthalimide tracer. Cell. 1978 Jul;14(3):741-59.

[2]. Transport of lucifer yellow CH into plant vacuoles--evidence for direct energization of a sulphonatedsubstance and implications for the design of new molecular probes. FEBS Lett. 1997 Dec 22;420(1):86-92.

Fluorescent yellow carbohydrazide dye is an organic dilithium salt with a counterion of 6-amino-2-[(hydrazylcarbonyl)amino]-1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinoline-5,8-disulfonic acid. It is a fluorescent dye. It contains fluorescent yellow carbohydrazide dye (2-).
Lucifer Yellow CH is a highly fluorescent, fixable tracer dye used in cell biology and neuroscience research. It contains a free hydrazido group that reacts with aliphatic aldehydes, allowing it to be fixed to tissue. The dye is used to label cells, visualize morphology, and assess gap-junction communication. This product is for research purposes only and is not for human therapeutic use.

C13H9LI2N5O9S2

457.25100

457.016

C, 34.15; H, 1.98; Li, 3.04; N, 15.32; O, 31.49; S, 14.02

67769-47-5

Lucifer Yellow CH dipotassium salt;71206-95-6

93367

Yellow to orange solid

1.376

4

11

0

31

914

0

C1=C(C=C2C3=C1C(=C(C=C3C(=O)N(C2=O)NC(=NN)[O-])S(=O)(=O)O)N)S(=O)(=O)[O-].[Li+].[Li+]

RPKCZJYDUKVMGF-UHFFFAOYSA-L

InChI=1S/C13H11N5O9S2.2Li/c14-10-5-1-4(28(22,23)24)2-6-9(5)7(3-8(10)29(25,26)27)12(20)18(11(6)19)17-13(21)16-15;;/h1-3H,14-15H2,(H2,16,17,21)(H,22,23,24)(H,25,26,27);;/q;2*+1/p-2

1H-Benz(de)isoquinoline-5,8-disulfonic acid, 6-amino-2-((hydrazinocarbonyl)amino)-2,3-dihydro-1,3-dioxo-, dilithium salt

2934.99.03.00

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture and light.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : ~25 mg/mL (~54.67 mM)

Solubility in Formulation 1: 10 mg/mL (21.87 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.

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 (Please use freshly prepared in vivo formulations for optimal results.)