Studies on the batch adsorption of plasmid DNA onto anion-exchange chromatographic supports.

摘要: The adsorption of a supercoiled 4.8 kbp plasmid onto quaternary ammonium anion-exchangers was studied in finite bath. Equilibrium experiments were performed with pure plasmid, at 25 degrees C, using commercial Q-Sepharose matrices differing particle diameter (High Performance, 34 microm; Fast Flow, 90 and Big Beads, 200 microm) recently commercialized ion-exchanger, Streamline QXL (d(p) = different salt concentrations (0.5, 0.7, 1 M NaCl). Plasmid found to follow second-order kinetics (Langmuir isotherm) average association constants K(A) 0.32+/-0.12 mL microg(-)(1) 0.25+/-0.15 microg(-1) 0.5 0.7 Nacl, respectively. maximum binding capacities not dependent on the ionic strength range 0.5-0.7 but decreased increasing diameter, suggesting that mainly occurs surface particles. No NaCl. A nonporous model applied describe uptake rate overall process controlled by mass transfer regions low relative amounts adsorbent (initial stages) kinetically later stages for high adsorbent. forward reaction constant (k(1) 0.09+/-0.01 mg(-1) s(-1)) film coefficient (K(f) (6 +/- 2) x 10(-4) cm calculated. Simulations study effect amount rate, yield, media capacity utilization.