Question

1. The final concentration of dNTPs in a PCR should be 1 mM. You currently have each nucleotide as separate 10 mM stocks. How would you made up 400 µl of a dNTP mix?
2. You are given a 8 mM solution of a protein (MW 27,000 g/mol). Using this information fill in the blanks below to fit the units given.

1. ____________________μmole/ml
2. ___________________ g/L
3. ___________________ mg/ml

3. You order a 19-mer oligonucleotide for a PCR reaction. The molecular weight is 5858.9 and the amount you receive is 36.7µg. You need to make up a 5µM solution. What volume of water do you dissolve your oligo in?
4. You lypholize 1ml of a 20nM solution of a 50kDa protein dissolved in water. What is the expected weight of the dried protein?
5. If the average molecular mass of an amino acid is 110Da, what would the estimated molecular weight of a 33-mer peptide be? (in kDa)

Answer 1

Either we can add 10 μl of each dNTP of total 40 μl and then addition of 360 μl of nuclease free PCR grade water to prepare 400 μl PCR mix or as mentioned in the image.

We need to dissove the oligo in 1.25 ml water as calculated in the above image.

Expected weight of dried protein is 1 μDa,

Estimated molecular weight of the 33 mer peptide is 3.63 kDa.