Figure 1.
MDA strategy and product characterization. (A) Random-primed rolling circle amplification of circular DNA templates. DNA synthesis is initiated with random oligonucleotide primers. 3′ Ends are indicated by arrowheads. Thickened regions indicate primers. Secondary priming events occur on the displaced product DNA strands. (B) Scheme for MDA of genomic DNA. Secondary priming events are initiated from primary products. (C) Effect of template concentration on amplification yield. A total of 100 fg to 100 ng human genomic DNA was amplified by MDA at 30°C as described. Aliquots were taken from single reactions at the times indicated to quantitate DNA synthesis. ●, 10 ng genomic DNA template; ○, 1 ng; ▴, 100 pg; ▵, 10 pg; ■, 1 pg; □, 100 fg; ⧫, primers omitted. (D) Denaturing gel analysis of amplification product size. Radioactively labeled amplification products shown in C were electrophoresed through an alkaline agarose gel (1%), and the dried gel was exposed to a phosphor screen and imaged as described. Reaction products were loaded in order of increasing DNA template amount, as indicated above the gel.