Trypan blue is a widely used dye in biological research, particularly in cell viability assays. When cells die, cell membranes become permeable to trypan blue, allowing the dye to enter the cell and stain proteins. As a result, viable cells with intact membranes remain unstained, while dead cells are stained blue. This principle is the basis for the trypan blue exclusion assay, a common method to determine cell viability.
However, it is well known that trypan blue staining solutions used in laboratories often experience precipitation depending on storage conditions, and once a trypan blue staining solution has precipitated, it is difficult to use for cell staining.
In this article, we will discuss the causes of trypan blue precipitation and methods for recovering a precipitated trypan blue solution for use in cell staining.
Precipitation of Trypan Blue (TB) solution is quite common and typically increases during storage when external temperatures decrease.
Figure 1. Comparison of 1 mL of TB (0.4% liquid solution) during storage at the 4-week mark at different external temperatures; TB solution made by two different manufacturers.
Warming precipitated TB solution to 37℃ for 10 minutes has been shown to effectively remove precipitation.
Figure 2. Comparison of 1 mL of TB (0.4% liquid solution) during storage at the 4-week mark at 4℃ and -20℃ and then with temperature increased to 37℃ for 10 minutes using Logos Biosystems TB solution.
|Trypan Blue Stain is a vital dye used to assess cell viability. Viable cells have intact cell membranes and are not stained, remaining colorless. Nonviable cells are stained blue. Viable cells have intact cell membranes and are not stained, remaining colorless. Nonviable cells are stained blue.|
|Trypan Blue Stain is used with the LUNA™ family of cell counters for brightfield cell counting. Trypan Blue Stain is a toxic compound, customers should take all relevant precautions when handling it (ie gloves). When heating TB, it’s important to keep the cap on the tube, due to toxicity.|
Are you looking for an automated cell counter that can be used with trypan blue staining? Logos Biosystems offer a range of automated cell counters that are compatible with various staining methods, including trypan blue.