Sterilise the bits you need for expressing. When you've finished, clean & sterilise the bits you've used together with the teat & leave it in the steriliser until you're ready to use it. Also wash hands & use alcohol gel before removing items from steriliser.
BM is exactly the same as formula in that all items that come in contact with BM must be sterilised.
Hi - I used to put the bits I was using in the steriliser first (I had an Avent pump with a pot to catch the milk), assemble and pump and while I was expressing put the lid for the pot in so it was ready to pop on when I was finished. However, I think I am maybe a bit OTT with sterilising as I know a few folk who just use hot soapy water for anything to do with EBM..
Going to start expressing and am sterilising the bits now. instructions say things are sterile until steriliser is opened (microwave type) but as the bottle attaches to the pump what about the teat / lid ? should I be sterilising them while expressing so they stay sterile ? or do them all together and leave them in the steriliser until I'm ready ?