Cell bio lab cancer pharmacology

The cell counter automatically counts the green, living cells and the red, dead cells. Check the cell count and answer the following question: What is the total number of viable cells in the cell suspension, keeping in mind previous dilutions? a) 3.3 x 105 cells/mL b) 1.65 x 105 cells/mL c) 1.77 x 105 cells/mL d) 1.22 x 104 cells/mL

, a) 3.3 x 105 cells/mL

Our stock solution is at 50 mM. How much of this do I need to make 5.5 mL of a working solution at 1 mM? Use the formula C1 x V1 = C2 x V2 a) 110 µL b) 11 µL c) 1.1 pL d) 0.11 µL

a) 110 µL

It looks like Dr. Parsimony's worrying report about false-negatives holds true. We know that cyclophosphamide is normally used to treat cancer patients in the clinic. The drug is rapidly absorbed and then metabolized in the liver to the active form. However, we couldn't detect any effect in the MTT assay? Why is this the case? a) Because the assay is performed in vitro b) Because not enough MTT was added c) Because we measured at the wrong absorbance d) Because the cells did not grow sufficiently

a) Because the assay is performed in vitro no liver cells there for generating metabolic activity

In the case of cyclophosphamide, how can the in vitro assay be modified to avoid a false negative result. a) Include liver homogenates in the culture medium b) Include other drugs that enhance the activity of cyclophosphamide c) Increase the concentration of cyclophosphamide d) Increase the concentration of serum used in the culture medium

a) Include liver homogenates in the culture medium mitochondrial enzymes present in this homogenate will metabolize the prodrug into cytotixic metabolites

It's time to add the MTT reagent to both plates. To which wells do we need to add MTT reagent? a) To all wells b) To all wells except lanes 1 and 2 c) To all wells except lane 2 d) To all wells except lane 1

a) To all wells

Why do we need to incubate the cells for 24 hours before adding the drugs? a) To make sure the cells are not proliferating before treatment with drugs b) To enable the cells to adapt to the new conditions c) To give the cells the chance to repair any damage caused by drugs d) To give the cells time to adjust to the MTT reagent

b) To enable the cells to adapt to the new conditions

In the next step, the mean absorbance from the blank values is... a) .added to all other values b) ...multiplied with all values c) ...subtracted from all other values d) None of the options is correct

c) ...subtracted from all other values

For the experiment with both drugs, we will need 55 mL of the cell suspension. The total number of cells in our suspension is 3.3 x 105 cells/mL. What volume of this cell suspension is required for a final concentration of 1x104 cells/mL? a) 0.16 mL b) 16.6 mL c) 1.66 mL d) 1.66 pL

c) 1.66 mL

Good job! You just added 20 µL of 1 mM epirubicin to 180 µL of cells. What is the final concentration of the drug that the cells will be exposed to? a) 1 mM b) 10 µM c) 100 µM d) 1 µM

c) 100 µM

What is the first step you would take in analyzing the absorbance data to build a dose-response curve? a) Subtracting the blank values from all the other values b) Subtracting the control values from all the other values c) Calculating the mean absorbance of each lane d) Calculating the mean absorbance of each row

c) Calculating the mean absorbance of each lane

Neat work! Looking at the dose-response curve, what is your conclusion? a) Both drugs show an effect b) Only cyclophosphamide shows an effect c) Only epirubicin shows an effect d) Neither of the drugs shows an effect

c) Only epirubicin shows an effect - increasing concenmtration, less absorbance can be observed, which indicates a stronger effect of the drug on the cells' metabolic activity. this is not the case for cyclophosphamide

What does the EC50 of a drug define? a) The number of cells affected at 50% of the stock concentration b) The enhanced concentration at half-maximal activity c) The half-maximal effective concentration d) The empirical concentration in 50% of the cell population

c) The half-maximal effective concentration - concentration of a drug where 50% of its maximal effect is observed

What is the aim of the in vitro screen performed at the institute? a) To analyze the usefulness of robots in compound screening b) To study the chemical composition of compounds c) To identify potential anticancer compounds d) To characterize the morphology of cancer cells

c) To identify potential anticancer compounds

Why is no drug added in lane 2 of the plates? a) To serve as the positive control b) To serve as a blank for the assay c) To serve as the negative control d) To avoid a spill over to lane 1

c) To serve as the negative control

All raw data are stored in the system and can be seen on the screen next to the spectrophotometer. Before compiling them into a graph and determining the EC50, let's review a few things. In which well would you expect the highest absorbance in the epirubicin-treated plate? a) Lane 3 b) Lane 12 c) Lanes 1 and 12 d) Lanes 1 and 2

d) Lanes 1 and 2 Cells in lanes 1 and 2 were not treated with the drug and therefore have the highest metabolic activity and absorbance

What is MTT used for in this protocol? a) As a negative control b) As a supplement for cell growth c) To dilute the drugs d) To measure cell survival

d) To measure cell survival