Julia wants to prepare a protein sample for SDS-PAGE analysis. She decides she will make a mixture containing 30 uL of protein sample plus the necessary amount 6x SDS-PAGE loading buffer, and add half of it to the gel. How much (in uL) of each of the following components should Julia mix together to prepare the mixture?

a. 6x SDS-PAGE loading buffer

B. Protein sample

c. How much of the mixture should she add to the gel to deliver 15 uL of her original protein sample?