PRE-PUBLICA TION EDITION - Nelson Education

f2.D.1. Microscope SkillsThe basic microscope skills are presented asinstructions. This allows you to practise theseskills before you need to use them in the activitiesin Nelson Science Perspectives 10.Materials• scissors• microscope slide• cover slip• medicine dropper• compound microscope• compass or Petri dish• pencil• transparent ruler• small piece of newspaper with writing• small piece of onion membrane• water• two pieces of thread, different coloursPreparing a Dry MountA dry mount is a way to prepare a microscope slidethat does not use water.1. Find a small, flat object, such as a single letter cutfrom a newspaper article. A letter “e” works well.2. Place the object in the centre of a microscopeslide.3. Hold a cover slip between your thumb andforefinger. Place the edge of the cover slip toone side of the object (Figure 5). Gently lowerthe cover slip onto the slide so that it coversthe object.fPreparing a Wet MountA wet mount is a method of preparing a microscopeslide that uses a drop of water.1. Find a small, flat object such as a piece of onionmembrane.2. Place the object in the centre of a microscopeslide.3. Place one or two drops of water on the object(Figure 6).Figure 64. Holding the cover slip with your thumb andforefinger at a 45° angle, place one edge of thecover slip on the slide (Figure 7). Gently lowerthe cover slip, allowing the air to escape.Figure 7Viewing Objects Under the Microscope1. Make sure that the low-power objective lens ispositioned over the diaphragm. Either raise theobjective lens or lower the microscope stage asfar as possible. Place your dry-mount preparedslide in the centre of the stage. Use the stage clipsto hold the slide in position. Turn on the lightsource (Figure 8).ffFigure 5Figure 8606 Skills Handbook NEL