Medela does not suggest the use of bottle liners as anything placed into the bottle can interfere with the valve assembly causing lack of suction. If you wish to use a bottle liner, pump into Medela bottles and then pour the collected breastmilk into the bottle liner.
This Question Applies to:
Breastmilk Bottle Set - 8 oz
Breastmilk Bottle Single - 5 oz
Breastmilk Feeding Gift Set
Breastmilk Storage Solution™