Coelenterazines are predominantly yellow solids, but may contain dark red or brown flecks. This does not affect product stability or performance. If your coelenterazine is uniformly brown, then it is oxidized and needs to be replaced.
Most of our products are stable at room temperature for many days, but we recommend storage at 4°C or -20°C to prolong shelf life. In the case of many of our aqueous dye solutions, the compounds are very stable at room temperature, but we recommend cold storage to prevent the growth of mold or other microbes over time. Therefore, to save on shipping costs, products with recommended storage at 4°C or -20°C may ship at ambient temperature or with an ice pack. These products may thaw without affecting product performance. When you receive the product, place it under the recommended storage conditions.
Most of our products are stable at room temperature for many days, so in all likelihood the product will still work just fine. To be on the safe side, we recommend performing a small scale positive control experiment to confirm that the product still works for your application before processing a large number of samples or precious samples.
One exception that we are aware of is GelGreen™, which is more sensitive to light exposure than most of our other fluorescent dyes. If GelGreen™ is exposed to ambient light for a prolonged period of time (days to weeks), its color will change from dark orange to brick red. If this occurs, the GelGreen will no longer work for gel staining.
TrueBlack® Lipofuscin Autofluorescence Quencher, 20X in DMF, is a novel reagent that quenches lipofuscin autofluorescence in tissue sections for immunofluorescence staining.
Eliminates lipofuscin autofluorescence
Reduces autofluorescence from non-lipofuscin sources
Doesn’t cause high background, unlike Sudan Black B
Can be used before or after immunofluorescence staining
Clears the way for fluorescence imaging of human and aged animal tissues
TrueBlack® effectively eliminates lipofuscin autofluorescence in tissues like human and mouse brain and retina (see Figs. 1-3 and TrueBlack® References). Lipofuscin consists of highly autofluorescent granules of oxidized proteins and lipids that build up in the lysosomes of aging cells. Lipofuscin granules fluoresce brightly in all channels used for fluorescence microscopy, and accumulate in a variety of cell and tissue types with age. Consequently, imaging of specific immunofluorescence signal in certain adult human tissues or aged animal tissues can be virtually impossible unless methods are employed to quench or mask lipofuscin fluorescence.
TrueBlack® quenches lipofuscin with less background than Sudan Black B
Traditionally, Sudan Black B has been used to quench lipofuscin autofluorescence by incubating tissue sections with the dye after immunofluorescence staining. However, while it masks the autofluorescence from lipofuscin, Sudan Black B also introduces uniform non-specific background fluorescence in the red and far-red channels (Fig. 1), limiting the use of fluorescent dyes in those wavelengths. Now Biotium has developed TrueBlack® as a superior alternative to Sudan Black B. TrueBlack® quenches lipofuscin fluorescence with far less increase in red/far-red background fluorescence (Fig. 1). TrueBlack® treatment can be performed before or after immunostaining. It is rapid, simple, and has minimal effect on signal from fluorescent antibodies or nuclear counterstains, thus preserving the signal-to-noise ratio of the immunostaining (Figs. 2-3).
TrueBlack® can reduce autofluorescence from sources other than lipofuscin
TrueBlack® also can reduce autofluorescence from other sources, such as collagen, elastin, red blood cells, and general background fluorescence. It is not as effective at quenching these sources of autofluorescence as it is for lipofuscin, but it can improve background in human and non-human tissue types (Figs. 4-5). TrueBlack® also has been used to quench background fluorescence on polycarbonate filters used as cell supports for imaging cytometry.
A revolutionary antifade mounting medium optimally formulated for preserving fluorescence of our CF® dyes and other fluorochromes. EverBrite™ Hardset mounting medium hardens at room temperature completely in 24 hours.
Pens to draw a water repellent circle around slide mounted tissue and prevent the waste of valuable reagents by keeping the liquid pooled in a single droplet. Available in regular (4 mm tip) and mini (2.5 mm tip).