Susan,
We used to use those tubes you are speaking of.  They are sterile and
cheap and come in bags of 20.  As we took smaller and sicker premies we
realized that we were doing what we considered to be too much pouring
(and so risking contaminating the milk).  These tubes don't fit onto the
pump kits so a mother has to pump into another bottle and then pour into
the storage tubes.  Then, when a nurse is to feed the baby, and has to
add fortifier or something else to the milk, she pours it from the tube
into an unsterile volufeed to mix and feed.  Now, what are trhe chances
of contamination of themilk?  And if you use storage bags (not
recommended), the risks of contamination are even greater.  I am seeking
an answer to the nonsterile volufeeds.  When I find one I will post it!
Edie Armstrong BSN, IBCLC, Fairfax, Va.