Hi, need some help and advice with sterilising please. We have a Tommee Tippee microwave steriliser. These can sterilise multiple bottles and items at once. They say that when sealed and unopened the contents remain sterile for 24 hours. What I would like to know is, once I open it and take a bottle out to be prepared and there is a bottle remaining in the steriliser. Will I have to sterilise it again at the next feed as it has been opened. Or is there some way I can keep the remaining bottle and items sterile? Thanks for the help guys this is our first born boy.