AN AUTOMATED-METHOD FOR THE DETERMINATION OF DEOXYRIBONUCLEASE ACTIVITY AS EXEMPLIFIED BY FRACTIONATION OF THE COMPONENTS OF THE MEDICAMENTVARIDASE(R)

The activity of most deoxyribonuclease enzymes can be monitored by mea suring the change in absorbance at 260 nm which accompanies the breakd own of the double-stranded structure of native DNA. An automated metho d for determining deoxyribonuclease activity, based on such an absorba nce change, which can overcome problems of inhibition/activation arisi ng from the presence of inorganic cations, is described. Variations in inorganic cation concentration is a particular problem when measuring the activity of chromatographic fractions eluted via a salt gradient. A comparison is made between the automated and a manual method for th e assay of deoxyribonuclease active constituents, of the medicament 'V aridase', eluted from a Cellex-D (Bio-Rad Laboratories Ltd) anionic ex change resin using a 0.05-1.0 M sodium chloride gradient.