Answers to Review Questions in Pipetting

1. Give the reasons why the thumb is not used in pipetting.

The thumb should not be used because, it is more convenient to use the index finger. You can manipulate the pipette properly and easily.

2. Convert the following milliliters to microliters.

5 ml - 5,000 uL
20 ml - 20,000 uL
0.05 ml - 50 uL
100 ml - 100,000 uL
0.025 ml - 25 uL

3.Name sources of error in pipetting.

Broken tips can reduce the total volume TV) of the pipet.

Not wiping the sides of the pipet before delivering will add to the TV.

Dirty and contaminated pipets can affect the test reaction.

Reading at the lower meniscus for opaque solutions instead of the upper meniscus and vice versa.

Improper pipetting will lead to unreliable results.