Question

1. Let’s assume a single tumor cell has 1000 copies of PSA (prostate specific antigen) inside of it. To detect PSA, we will isolate 700 cells and resuspend those cells in 100 microliters of buffer, and we lyse (burst) open all of the cells, and we’ll put this all in Test tube A. Then we’ll take the contents out of testube A, and then we will use our new fancy biosensor to try to detect the PSA. Our biosensor detection limit is 4 pg/ml.

A) How many moles of PSA do we have in testube A?

B). What is the detection limit of our biosensor in terms of molarity.

C) Is our sensor sensitive enough to detect the PSA from Testube A?

D) Now let’s assume we resuspened only 10 cells in 1 microliter of volume. What is the new molarity? Would our biosensor be sensitive enough to detect the PSA?

Answer 1