microscopes and magnification

• Magnification - how much bigger the image is than the actual specimen
• Resolution - the ability to distinguish between 2 points
• 1. ocular lens (eye piece) - mostly X102) body tube3) nosepiece4) objective lens - X10 to X 40 (in sch microscopes)5) arm6) stage7) stage clips8) diaphragm9) coarse adjustment knob10) fine adjustment knob11) light source12) base
• light microscopes are cheap, portable and could view live specimen
• light microscopes have low magnification (e.g. ribosomes can't be seen by it) and low resolution
• electron microscopes need to be complete in air-tight vacuum
• electron microscope use beam of electrons
• electron microscopes are more detail - could magnify by x2,000,000, 0.2 nm resolution
• electron microscope could only view dead specimen. they are expensive and not portable
• view under low power, then increase the magnification when using a microscope
• use pencil to draw diagramn
• don't sketch when drawing
• use ruler to draw labels
• write the label clearly
• include title and magnification
• draw a simple overview (if in low plan)
• label the cellular structures (if in high power drawing)
• Image size = actual size * magnification