1. When using the dropper, squeeze the rubber nipple with your finger to drive out the air in the dropper, and then stick the dropper into the reagent bottle. Let go of your finger and the reagent will be inhaled.
2. After taking the liquid, the dropper should be kept above the rubber head. Do not lay it flat or upside down to prevent the solution from flowing back and corroding the rubber head.
3. When adding liquid, it should be suspended above the beaker without touching the glass wall, so as to avoid contaminating the dropper or contaminating the reagent.
4. Do not put the dropper on the test bed or anywhere else to avoid staining the dropper.
5. Rinse the used dropper with clean water immediately for reuse.
6. Do not use the uncleaned dropper to absorb other reagents (do not flush the dropper on the bottle with water).