A lab assistant needs to mix up the following reaction to prepare DNA for an experiment:. 20ul of a DNA sample
20ul of enzyme
40 ul of reaction buffer
120ul of water
The smallest size tube that will hold the entire reaction is:. [0.025, 0.25, or 2.5] ml:
Which of the following pipetting devices could be used to accurately measure all the needed volumes? [P20, P200, P1000 or 1 ml graduated pipet with electronic pipet-aid]

Explanation:

The total solution formed after mixing the components will be

20 μl + 20 μl + 40 μl + 120 μl = 200 μl

The smallest size tube that will hold the entire reaction is:

Firstly convert 200μl to ml

1000 μl = 1 ml

200 μl = X

X = 200 x 1/1000

X = 0.2 ml

The smallest size tube (from the options provided in the question) is 0.25 ml.

The pipetting device that could be used to accurately measure all the needed volumes must be able to measure 20 μl, 40 μl and 120 μl.

The best pipette to accurately take these measurements individually is the P200 micropipette because it has an accurate/useful range of between 20 μl - 200 μl

if you listed your answers right then i believe your answer is b.