When preparing to "milk" a generator, which vial is placed on the generator first?

When preparing to "milk" a generator, the vial containing the extracting solution is placed on the generator first. This is typically done to ensure that the extracting solution effectively elutes the radioisotope from the generator. The solubilizing solution is crucial as it facilitates the release of the radionuclide from the column in the generator where it is bound to a solid support.

Placing the extracting solution vial first allows for a proper and efficient elution process, where the solution can draw out the desired radioisotope effectively. The subsequent steps in the process are reliant on the successful elution of the radioisotope into the extracting solution vial, making this initial step vital for the overall success of "milking" the generator.

Other options may refer to the role or timing of different vials in the process, but the primary function of the extracting solution vial at the start of the procedure is essential in achieving the desired outcome of obtaining a viable radioisotope for further use.