Microscopy and Food Tests
Microscopy is all about getting a clear view of tiny specimens like onion cells. Cut your specimen thin, add a drop of iodine stain, and carefully lower the coverslip to avoid air bubbles. Always start with the lowest magnification and work your way up whilst adjusting the focus knobs.
Food tests reveal what nutrients are hiding in your samples. You'll need to grind your food with distilled water, filter it, then test for different molecules. Benedict's solution turns green-yellow-red for reducing sugars, iodine goes blue-black for starch, Biuret reagent turns purple for proteins, and Sudan III creates a red layer for lipids.
Safety is crucial - wear goggles for all chemical tests and handle ethanol carefully since it's highly flammable. The emulsion test using ethanol will show a cloudy mixture if lipids are present.
Top Tip: Remember the colour changes - they're often the key to exam success!
