The smartest way to refill your empty TIPACK box & Reload Block With its top cover to keep tips clean from contamination during the transfer from the BLISTER REFILL to the TIPACK box, BLISTER REFILL are also available in sterilized version. The sterilization date is guaranteed for five years. Sterilized PIPETMAN TIPS are irradiated by gamma-rays for more efficient sterilization. Sterilized PIPETMAN TIPS are certified free of detectable DNA, RNA, DNase, RNase, ATP, Pyrogens and trace metals.