tubes to lock fe 3 o 4 and bound nucleic acid to sides of tubes aspirate unbound solution from the extraction tubes and transfer to waste transfer 370 u03bcl elution buffer to each extraction tube and mix the elution buffer has a basic ph the elution buffer was 177 8 mm bicine 88 3 mm koh 11 dmso and 12 1 glycerol position magnets next to extraction tubes to lock fe 3 o 4 to sides of tubes aspirate eluate from the extraction tubes and transfer to bd probetec u2122 et ct amplified dna assay collect normalize and average rox signals from passes 20 60 of the incubation in the bd probetec u2122 et instrument to assess ec extraction adequacy collect bd probetec ct assay results mota scores corresponding to the area under the amplification curve to assess the adequacy of ct target recovery and amplification the data below are presented in mota values for the ct determinations and in machine normalized rox values for the ec determinations free rox dye will not bind to ferric oxide under the conditions used for the extraction the mota values represent the sum of individual fluorescence measurements over time using a fluorometer with an established cutoff level for a positive reaction of 2 000 for the bd probetec u2122 et ct and gc amplified dna assays bd probetec u2122 brand assay kits are available from becton dickinson and company and are designed for use with use the bd probetec u2122 et system for strand displacement amplification sda the bd viper u2122 sample processor automates the sample handling associated with high volume testing using the bd probetec u2122 et system in all cases in which both ec and binding acid were present normalized rox values were u2267 1 89 in all.