|RS101-01||D-Luciferin potassium salt|
Content and storage
|Firefly Luciferin||1 g||-20 °C|
Protect from light
|When stored as directed, reactive probes are stable for at least 6 months|
|1 g is enough for 300 mice|
Color: Light yellow powder
Detection Method: Bioluminescence
Excitation Class: Visible
Molecular Weight: 280.32 g.mol-1
Cas Number: 2591-17-5
Shipping Condition: Dry Ice
Regulatory Statement: For Research Use Only. Not for use in diagnostic procedures
Luciferin is a small molecule that consists of a benzothiazole moiety attached to a thiazole carboxylic acid moiety. Luciferin is a natural substrate of luciferase, an enzyme found in Firefly luciferase. This molecule has fluorescent properties (Ex 328 nm; Em 532 nm in H2O)1,2 but it is mainly used for bioluminescent imaging (BLI) purpose.
Bioluminescence is a natural process that has been found in various living organisms such as the North American firefly (Photinus pyralis) and is based on the oxidation of D-luciferin catalyzed by the enzyme Luciferase. Upon recognition by the enzyme, D-luciferin is oxidized to oxy-luciferin and releasing one photon of light, which can be detected by a CCD camera (Figure 1). The intensity of the light output is closely related to the amount of D-luciferin available for the enzyme and therefore it is possible to quantify the amount of luciferin by measuring the amount of emitted light with a CCD camera. As a non-invasive imaging method, BLI is comparable to other in vitro and in vivo techniques but has the advantage of high sensitivity, convenience and ease of use. It does not require a light source (as opposed to fluorescence) and there is no background signal from tissues that do not express luciferase. Moreover, it allows real-time imaging of luciferase expressing cells or luciferase expressing mice.3-5 The luciferin/Luciferase process is very substrate dependent and does not allow significant modification on the luciferin scaffold to be recognized by the enzyme.
Figure 1: Oxydation of D-luciferin by Firefly luciferase forming oxy-luciferin and a photon of light
Guideline for use
D-luciferin for in vitro use:
– 1g of D-luciferin is dissolved in 33.3 mL of sterile water to make a 30 mg/mL stock solution. After mixing and filtering (0.2 um), the solution is aliquoted and purged with nitrogen (inert gas prevents oxidation) protect from light and freeze down to -80°C for future use. Frozen stock solutions can be stored up to 1 year.
– D-luciferin stock solution is thawed, kept on ice and protected from light. Stock solution is diluted at 1:200 in complete culture medium to 150 ug/mL. Luciferase expressing cells are incubated 5 min at 37°C prior to imaging. Diluted solution should be discarded after use.
D-luciferin for in vivo use:
– 1g of D-luciferin is dissolved in 66.6 mL of DPBS, w/o Mg2+ and Ca2+ to make a 15mg/mL solution. After mixing and filtering, the solution is aliquoted and purged with nitrogen (inert gas prevents oxidation) protect from light and freeze down to -80°C for future use. Frozen stock solution can be stored up to 1 year.
– D-luciferin solution is thawed, kept on ice and protected from light. Diluted solution should be discarded after use
– Mouse is injected IP with D-luciferin solution at 150mg/kg of body weight. Images are acquired after 10-15 min post-injection.
1. White, E.H. et al.,(1963) J. Am. Chem. Soc., 85, 337
2. Bowie, L.J., (1978) Methods in Enzymology, 57, 23
3. Prescher, J. A., and Contag, C. H. (2010) Curr. Opin. Chem. Biol. 14, 80-89.
4. McCaffrey, A., Kay, M. A., and Contag, C. H. (2003) Mol. Imaging 2, 75-86
5. Massoud, T. F., and Gambhir, S. S. (2003) Genes Dev. 17, 545-580.