Do not under any circumstances place the 40x objective in the oil
Use only the fine focus and refocus your specimen.
Nearly all organic solvents, and especially xylol and toluene, are potentially hazardous. They are flammable and readily enter the boddy by direct absorption through the skin or lungs. Consistent high exposure to thses solvents has been linked with liver damage and potential carcinogenesis. Use all solvents sparingly when needed and always in a well- ventilated area.
Once oil is placed on the slide, the 10X and 40X objectives will no longer be useful until the oil is removed. The oil will blur any image attempted with the lower magnifications. Use oil only when necessary and after completing all work at the lower magnifications. In order to return to work at the lower magnifications, the slide must be completely cleaned of any residual oil and dried. For this reason, oil immersion is employed only when necessary, and only after thorough observations at the high dry magnification (40X). 11
________________________________________________________________ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |_______________________________________________________________| Drawing of bacterial cell types
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