Gram Stain
The Gram Stain Purpose: To identify and classify bacteria that has proved valuable for diagnosing certain diseases. It differentiates between two groups, a gram positive which retains the primary dye and stain purple because they resist decolorization with an organic solvent. A gram negative do not retain the primary dye because they are decolorized, they lose the purple color and become colorless. Procedure: As stated in the lab manual for The Gram Stain are pages 24-27, are are continued with pages 50-51. Results: Escherichia Coli: • Stained red rods, lots of them • Very small shaped rods • Oil immersion • Gram negative stained because were a very bright red color Bacillus Subtilis: • Long shaped rods liked together • Very light color, seemed as it was very clear • Gram negative because the color seemed very light and barely could see • Oil immersion Mix: • Little strands scattered around almost rod shaped • Then could see some linked together • Oil immersion Unknown #23(gram stain) • Gram positive very dark purple • Coccus shaped and formed grapelike structures • Oil immersion Unknown #23(wet mount) • Long rod shapes • There was Brownian motion where it was vibrating more • Oil immersion (* I did not find pictures of the Staphylococcus epidermidis or Neisseria sicca*) Tooth scrapping: • A lot of purple, red, orange • Looks as if it were a cloud with all the colors • Lots of gram positive • Lots of pinkish bacteria, and lots of particles • Particles are mainly in clusters • Used oil immersion lens Discussion In the gram stain experiment we were taught how to get the bacteria and heat-fix to the slide and then prepare it for a gram stain.