ratio of 1 unit dnase per 50 units of taq dna polymerase this was incubated at 37 u00b0 c for 22 hours the dnase was heat inactivated at 75 u00b0 c for 15 mm in the presence of 0 03 m dtt and 10 mm egta ph 8 0 ficoll 70 ficoll 400 and melezitose were mixed until dissolved at 2 8 u00b0 c to final concentrations of 9 6 9 6 and 15 respectively in the presence of 10 u00d7 cycle sequencing buffer the resultant solution was sterilized using a 0 2 u03bcm cellulose acetate filter the taq dna polymerase ready to go mix was generated by mixing the following components in a clean sterile polycarbonate bottle to the final concentrations using dnase and rnase free water u2014 1 u00d7 carbohydrate excipient mix 0 60 mg ml bsa 0 5 mm dna polymerization mix and 0 35 units u03bcl taq dna polymerase the reagents were stirred for gt 30 min at 4 u00b0 c the freeze drying procedure involves the following the bead dropping process dispenses the bulk taq dna polymerase ready to go mix in 10 u03bcl aliquots containing 3 5 u taq dna polymerase that are immediately frozen by submersion in liquid nitrogen this can be achieved by using either an automated bead dropper device or a standard laboratory pipette the beads are removed from the liquid nitrogen using a sieve that ensures that beads exhibit a spherical shape with consistent diameter size and weight sieving is accomplished at low humidity lt 15 the resultant beads are subjected to drying using a virtis freeze drier set at u2212 46 u00b0 c under vacuum for 48 hours to generate the.