b. do serial dilutions :
i. label four small test tubes as A, B, C, D
ii. using blue pipettor and blue tip, take 0.5 ml (= 500 ul) of stock dye and add it to test tube A
iii. add 4.5 ml of water to test tube A
now you have a one in 10 dilution of stock, written as 1:10
iv. using yellow tip and 50-200 ul pipettor, take 0.1 ml (= 100 ul) of solution from tube A, and place it into tube B, add 900 ul water
now you have a 1 in 100 dilution of stock, written as 1:100
v. using yellow tip and 50-200 ul pipettor, take 0.1 ml (= 100 ul) of solution from tube B, and place it into tube C, add 900 ul water
now you have a 1 in 1000 dilution of stock, written as 1:1000
vi. using white tip and 0-10 ul pipettor, take 0.01 ml (=10 ul) of solution from tube A and place it into tube D, add 990 ul of water
now you have a 1 in 1000 dilution of stock, written as 1:1000compare the color in tube D with that in tube C; they have the same concentration of dye
5. Mini-lab practical When you have completed all of the procedures and the work in the lab manual, you should take the mini-practical set up in the prep room. Take only a sheet of paper and a writing utensil.
Reminder : there will be a 10 pt quiz next week, so review this material before then !!
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