Characterization of DNA analogs. ( A ) PCR assays analyzed by 5% native polyacrylamide gel electrophoresis. Total PCR volume 100 µl: 20 ng 418-bp DNA template (pJ1506), 0.4 mM each LJM-3222 (5'-G TA CGC AG T ) and LJM-3223 (5'-TGTGAGT AGCTCACTCAT AG ), 0.2 mM each dNTP with indicated analog triphosphate ( 1–9 ) completely replacing appropriate dNTP, and 5 U DNA polymerase (indicated with plus symbol) with associated buffer and cycle conditions. Taq DNA polymerase ( Taq ) conditions: Taq DNA polymerase buffer with 100 mg/ml BSA and 2 mM MgCl ; 98°C (3 min), 30 cycles of [94°C (30 s), 60°C (30 s), and 72°C (45 s)], 72°C (5 min). PrimeSTAR HS DNA polymerase (PS) conditions: PrimeSTAR GC buffer with 2 M betaine; 98°C (3 min), 30 cycles of [98°C (15 s), 60°C (5 s), and 72°C (45 s)], 72°C (5 min). Pwo SuperYield DNA Polymerase ( Pwo ) conditions: Pwo PCR buffer with GC-rich solution and 2 M betaine; 98°C (3 min), 30 cycles of [98°C (1 min), 60°C (2 min), and 72°C (8 min)], 72°C (5 min). Lane 1 is marker (M) DNA (100 bp DNA ladder, Invitrogen) with 400 - and 500-bp bands indicated. ( B ) Anion exchange chromatography of 98-bp DNA-like polymers (pJ1923). Following equilibration in 20 mM Tris–HCl, pH 8 (buffer A), samples were eluted over 25 min at a 1 ml/min flow rate in a linear gradient from 50 to 100% buffer B (buffer A plus 1 M NaCl). Eluent absorbance at 260 nm (milli-absorbance units) was monitored with elution time (min).