Using Micropipets, Transfer Pipets, and a Balance

1

Entered testing area wearing closed-toed shoes, then donned proper PPE glasses/safety glasses/goggles and gloves (lab coat is optional)

2

Labeled 3 microcentrifuge tubes: for example, p200, p1000, and TP

3

Weighed each tube and recorded its mass on the paper provided

4

Pipetted 200 µl of the liquid provided into the tube labeled for p200 use. Judge verified competitor (i) selected 20-200 µl micropipet, (ii) set it to 200 µl, (iii) used an appropriate pipet tip, and (iv) transferred liquid without air bubbles or losing sample in the transfer process

5

Repeated Step 4.

6

Pipetted 100 µl of the liquid provided to the tube. Closed the tube tightly. (Judge verified competitor (i) set the 20-200 µl micropipet to 100 µl, (ii) used a proper pipet tip, and (iii) transferred liquid without air bubbles or losing sample in the transfer process.)

7

Pipetted 500 µl of the liquid provided to the tube labeled for p1000 use. Closed the tube tightly. *Judge verified competitor (i) selected 100-1,000 µl micropipet, (ii) set it to 500 µl, (iii) used a proper pipet tip, and (iv) transferred liquid without air bubbles or losing sample in the transfer process

8

Transferred 500 µl of the liquid provided to the tube labeled for transfer pipet use. Closed the tube tightly. *Judge verified competitor filled the transfer pipet to the appropriate line without air bubbles and transferred the entire volume to the tube.

9

Weighed all three microcentrifuge tubes and recorded mass of each on the paper provided

10

Calculated the mass of the liquid in each tube (in g) and recorded it on the paper provided. *Judge verified calculated mass and that the mass of liquid in each tube was ~0.50g (the mass of the liquid transferred using the transfer pipet may differ). Judge confirmed correct units (g) and number of significant figures were used (for example, 0.50 g).

11

Cleaned work area: a. Disposed of used pipet tips, microcentrifuge tubes, and transfer pipet in waste receptacle. 2 0 b. Cleaned work area with surface disinfectant. 2 0 c. Removed PPE. 2 0 d. Washed hands or used alcohol-based hand-rub for hand hygiene. *Judge verified steps 11 a-d were performed in the order written here.