There are six stations for you and your lab partner to visit on your lab tour today. Some will be guided tours with a TA or faculty there to help you and others are self-guided, leaving you and your partner to try things on your own. Your visit to each station will last 10-15 minutes. It doesn’t matter which station you visit first but you must visit them all before you leave today. Your lab practical next time will assess your mastery of each station.
Introduction to pipetting
Someone will show you how to use your pipetmen and then you will use them to dilute a blue dye (0.01% Xylene Cyanol).
- If you have never used pipetmen then you should practice by pipeting 800, 80 and 8 ul of the 0.01% XC stock into eppendorf tubes. XC is not hazardous but it will stain your clothes. Pipet each volume three times and visually inspect how well the volumes match.
- Using your P20, measure 10, 15 and 20 ul of the 0.01% XC stock solution into the bottom of three cuvettes. Using your P1000, add water to bring the final volume to 1 ml (=1000 ul).
- Using your P200, measure 20, 50 and 100 ul of the 0.01% XC stock solution into the bottom of three more cuvettes. Using your P1000, add water to bring the final volume to 1 ml.
- Using your P1000, measure 100, 200, and 400 ul of 0.01% XC solution into the bottom of three more cuvettes. Add water to bring the final volume to 1 ml.
- With a gloved hand or with a piece of parafilm over the lip of the cuvette, invert each cuvette several times to thoroughly mix the contents.
- Visually compare your dilutions to the reference ones. If time permits, you will read the absorbance of your dilutions in the spectrophotometer so do not throw them away.