Pipetting: Master the technique (Labster)
Score: 140/140
• The Bradford assay only works at low protein
concentrations from .05 2.5 mg/mL proteins.
How can I reduce the concentration of protein
in our sample?
A. Evaporate the sample
B. Dilute the sample
C. Concentrate the sample
D. Purify the sample
• Why are only sterile Pipette tips in the lab?
A. To prevent reproduction of proteins
B. To avoid contamination of the sample
C. To make sure that the tips can be reused
D. To make pipetting more precise
• What is the upper limit of a p1000 pipette?
1000 μL
• What is the lower limit of a pipette p1000
200 Μl
• What is the volume range of the P1000
a. 20-200 ul c. .5-2 ul
b. 2-20 ul d. 200-1000ul
• How would you set the volume to pipette 20 ul
with the P20
a. 200 c. 20
b. 2 d. 2000
• Why did you press the plunger all the way
down to the second stop?
a. to mix the contents in the tube
b. to push out the remaining fluid from the
tip
c. to avoid contaminations
d. to draw up liquid
• What do you need to do next before pipetting a
different sample?
a. discard the pipette
b. sterilize the pipette
c. adjust the volume
d. discard the tip
• How much protein do you need to add to the
800 µL buffer in the first micro centrifuge tube
to make a 1: 5 dilution
a. 200ul c. 100ml
b. 500ul d. 100ul
• How much fluid you 1:5 dilution has to be
transferred to the second micro centrifuge to
containing 900 µL buffer to repair 81:50
solution
a. 10ul c. 100ul
b.200ul d. 50ul
• Why do you think we do not take the 20 µL
from the original stock and dilute it in the 980-
microliter buffer instead?
a. because that’s not a 1:50 dilution
b. it’s not as precise
c. that is not a dilution series
d. there’s no pipette for such small volumes
• The dye we added stains proteins blue how
does its color change with increasing protein
concentration
a. brown color intensifies
b. blue color diminishes
c. blue color intensifies
d. color stays the same
• Have a look at the BSA scatterplot in the
second tab. What is the range of a sorbent’s
values measures for the BSA standard?
a. 0.08 - 0.65 c. 0.05 - 0.5
b. 0 - 0.8 d. 0 - 0.6
• Which of the BHL solution falls into that range?
Have a look at the absorbance values in the
Raw data sheet to answer this question
a. 1:5 wells a1 & a2
b. 1:500 well c1 & c2
c. 1:5000 wells d1 & d2
d. 1: 50 wells b1 & b2
• Can you estimate the concentration of bhl in
the 1:500 solution? Find a concentration in the
standard curve which corresponds to the
average observance of the 1:500 dilutions
a. 7mg/ml c. 0.7 mg/ml
b. 0.07mg/ml d. 0.007 mg/ml
• What was the original concentration in the BHL
sample if the dilution is 1:500 and the
concentration is 0.07 mg/milliliters?
a. 3.5mg/ml c. 0.04 mg/ml
b. 0.35 mg/ml d. 35 mg/ml
