Gram staining is a quick, effective, and medically relevant identification test that has beome one of the most essential tools in bacterial classification. In this experiment, students will use this staining technique to examine the size, shape, arrangement, and gram status (+/-) of Escherichia coli, Bacillus subtilis, and Micrococcus luteus. Expt. 160 Understand gram staining and its medical importance Explore bacteria diversity and classification Practice slide preparation, cell staining, and microscope observation Identify common bacteria based on size, shape, arrangement, and gram status