There are a lot of different stain colors available, so you could come up with a lot of different things to try. (domesticimperfection.com)
Otherwise you can get different stained concrete designs as per your choice. (designtrends.com)
This allows the user to simply tune to a required stain, for as many different stains as are necessary — all without damaging the original tissue sample, which can then be used for other tests. (sciencedaily.com)