Prunes are sold either with their pits or already pitted. The form you choose should depend upon your personal preference and recipe needs.
Ideally, you should purchase prunes that are sold in transparent containers so that you can evaluate them for quality. They should be plump, shiny, relatively soft and free of mold. If the packages are opaque, ensure that they are tightly sealed so that the prunes will not have lost any moisture. As with any other dried fruit, try to purchase prunes that are not processed with food preservatives such as sulfites.
Prunes should be stored in an airtight container in a cool, dry and dark place where they will keep for several months. Storing them in the refrigerator will extend their freshness, allowing them to keep for about six months. Regardless of where you store them, make sure that when you open the container, you reseal it tightly to prevent the prunes from losing moisture.