BIOL240 Study Guide - Gram Staining, Methylene Blue, Crystal Violet
15 Aug 2014
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Skydrop: the fundamentals of biology lab review notes (240l) Simple staining procedure, a single stain is used and all cells and structures generally stain the same colour regardless of type. Used to see the morphological type of cells such as cocci, rods, spirals and. Used to see a white object on a white background. Two types of staining techniques: positive procedures for light microscopy, basic with positively charged chromophore, negative stain. Positive stain example was with methylene blue with blue chromophore resulting in positive blue staining of the microorganism. The light microscope consists of a lens system, a controllable light source and a geared mechanism for adjusting the distance between the lens and object. Image is magnified by ocular to make the virtual image. Magnification achieved is because of objective and ocular lens. Calibrated mechanical stage and fine adjustment knob are easily damaged. There is a condenser underneath the lens that collects and concentrates light.
