Breast milk bags

JR • Mommy of four !!!!👦🏼👧🏼🧒🏼👶🏼
This might be a stupid question, I am starting to pump to save for when I need to be out of the house for school/work. I recently purchased medela pump and save breast milk bags, do I need to wash before using, if so, what is the best way?!
Thanks :)