Why are stains used in prepared slides such as the ones you used in this lab? use complete sentences.

Stains are often used in the medical field to view how infected samples react to treatment. Since it may be difficult to follow the reactions, a dye is often used to make the process more clear. Alternatively, stains may be used on dead cells for education purposes. Different stains may be used to highlight parts of a cell so that students can see them in color. Whatever the purpose of staining a slide is, however, the reason for the staining always boils down to making it easier for the viewer to observe the specimen in some fashion. 
Hope that helps. :)