Simple Serial Dilution

You are asked to perform a "two fold" serial dilution of a bacterial culture with 6 test tubes. (the first tube being the original concentrate and you need to serial dilute it 5 times)

There is 10 mL of bacterial concentrate in the original concentration and you will be adding 5 mL of aliquat into each of the 5 new test tubes that only contain 5 mL of water.

How much of the original concentrate is found in the 5th dilution tube?

• 5 mL of the original concentration

• .3215 mL of the original concentration

• .625 mL of the original concentration

• .3125 mL of the original concentration