Please try to be as detailed as possible, thank you! a. You are given 16 l of pG
ID: 211736 • Letter: P
Question
Please try to be as detailed as possible, thank you!
a. You are given 16 l of pGEM4Z at 250 ng/l in a 1.5 ml microfuge tube. How much DNA do you have in the microfuge tube?
b. Next, you remove 1 ul, place it in a 0.5 ml tube, and add 98 ul of 0.1X TE. What is the concentration of the pGEM4Z in the 0.5 ml tube? How much DNA is in the 1.5 ml microfuge tube now?
c. The reading in the spectophotometer is 0.5 O.D. What concentration of DNA is indicated by the spectrophotomter? Is this consistent with the concentration in the original 1.5 ml tube (above)?
Explanation / Answer
a. Concentration = 250 ng/uL
Volume = 16 uL
Amount of DNA = 250 X 16 = 4000 ng = 4 ug
b.
Dilution = 1 uL + 98 uL = 250 ng/99 uL = 2.525 ng/uL
Remaining DNA in 1.5 mL tube = 4000 - 2.525 = 3997.474 ng
c. C = A/(e X l)
OD = 0.5
This corresponds to dsDNA concentration = 25 ug/mL = 25 ng/uL
Concentration from part a = 250 ng/uL
So, the data from the spectrophotometer is inconsistent.