Using a Pipette Filler Do NOT let the water get into the bulb Squeeze Valve A and bulb at the same time Put pipette in liquid then squeeze Valve S until the liquid is at the 0 mark Put pipette over new container then squeeze Valve E until the liquid is at the mark for how much you need to dispense Practice measuring out 4 mL Safety Pipet Filler This bulb-type safety pipet filler is designed for efficient one-hand operation. Made from natural rubber for better memory and resistance to chemical attack. Its three chemically resistant valves control the evacuation of air, liquid uptake and liquid dispensing. Expel air from the bulb by squeezing the “A” valve and the bulb at the same time. Draw liquid into the pipet by squeezing the “S” valve. To dispense liquid squeeze the “E” valve. To deliver last drop squeeze the small bulb next to the “E” valve.

Part 2—How to Prepare a Serial Dilution Place 4 mL of the 100% blue food coloring into Tube 1 and SET ASIDE. Do not use this tube again for the rest of the activity. Next, place 4mL of the 100% blue food coloring into Tube 2. Add 4 mL of water to Tube 2. (Tube 2 now has 8 mL total) Place your thumb over top of tube and shake gently Tube 1 Tube 2 SET ASIDE; NEVER REMOVE FOOD DYE FROM THIS TUBE! 4 mL water Part 2—How to Prepare a Serial Dilution Mix gently 4 mL blue food dye 4 mL blue food dye

Part 2—How to Prepare Serial Dilution Measure out exactly 4 mL of the solution from Tube 2 and put it in to Tube 3. (Tube 2 is back to being just 4 mL) Add 4 mL of water to Tube 3 and mix as before Continue this same process for Tubes 4-6. Tube 6 will have 8 mL of solution in it, simple measure out 4 mL of its contents and discard. Tube 2 Tube 3 Move 4 mL of Tube 2 to Tube 3 4 mL water Part 2—How to Prepare Serial Dilution 8 mL of food dye and water mixed Mix gently 4 mL of Tube 2’s mixed contents And so on….