There are a few options to potentially increase the color difference between cell types when staining and viewing under a microscope:
1. Use different colored stains for the two cell types. For example, stain one cell type with eosin (reddish) and the other with hematoxylin (blue). This will produce clearly distinguishable colors when viewed.
2. Increase the concentration of the stain. Higher concentration stains will produce darker, more intense colors that are easier to differentiate. However, you have to be careful not to overstain the cells.
3. Use multiple staining techniques. For example, stain one cell type with eosin, and the other with both hematoxylin and safranin. This will produce cells with both blue and red staining, as well as cells with only red staining.
4. Incubate the cells in the stain for different times. Incubating one cell type in the stain for a longer period will likely produce a darker stain color compared to the other cell type with a shorter incubation time.
5. Add a counterstain to one cell type. Counterstains are secondary stains that are added after the primary stain. They will produce cells with two distinguishable colors, making differentiation easier.
In summary, there are a few basic approaches you can take to maximize color difference when staining and visualizing mixed cell populations. Increasing stain concentration, using multiple staining techniques, and adding counterstains are generally the most effective methods.