Simple Stain Lab Essay Preview: Simple Stain Lab prev next Report this essay Page 1 of 3 Purpose: To teach the student the techniques involved in doing a simple stain. To show the three morphological types of bacteria. Materials: Cultures (agar slants). Micrococcus luteus. Bacillus subtilis. Rhodospirillum rubrum. Dyes. Safranin. Methylene blue. Gentian violet. (Crystal.