Microbiology Health Science Lab Exam

Microbiology Health Science Lab Exam What is the refractive index? The amount the light bends When light enters different materials the bending of the light changes and the image will looks skewed, what's a good example of this? A Straw in a glass of water What has the same refractive index as glass? Immersion oil What is the area seen through the microscope? field of vision How many different lenses are there? 4; Scanning lens 4X, lower power lens 10X, High dry lens 40X and oil immersion lens 100X What is the total magnification of scanning lens 10x4=40x What is the total magnification of low-power lens 10x10=100x What is the total magnification of high-dry lens 10x40=400x What is the total magnification of oil immersion lens 100x10X = 1000X magnification What are Negative stains good for and why Determining the size of cells because there is not sticking and the cells will not be distorted Does a negative stain stain and why The background is stained because the negatively charged chromophore is repelled by the negatively charged bacterial cell wall What are direct stains good for and why Determines cell morphology and arrangement; may be distorted What is the reason for fixing To get the bacteria to stick to the slide What are some affects of fixing Distortion of the cell kills most but not all of the bacteria Denatures enzymes