Question

Primers are short pieces of DNA that are used in PCR (Polymerase Chain Reaction), the process which is used in molecular labs to make copies of short stretches of a gene or genome. You have designed primes that have a Molecular Weight (MW) of 6000. It arrives as a dry sample in the quantity of 300 µg. How much water do you need to add to make a primer stock solution of 100 mM primers?

HINTS: Remember that mM is a concentration; Molar (M) = moles / L

Break it down into steps.

1) The first step – how many mmol of primer do you have? (this requires you to use the MW)

2) How much water do you need to add to your mass (mmol) of primers to make a concentration of 100 mM?

Answer 1

2.

100mM= x nmoles of lyophilized primer+(x ×10microliter of molecular grade H2O.

300microgram =300000nanogram

300000nanogram of primer is added with 3000000microliter pcr grade water.it wil be 100mM