Array analysis of symmetrical and asymmetrical PCR products. A. Signal intensity for hybridisation of symmetrical and asymmetrical PCR products of 312 and 317 bases, respectively, both with a 5′ segment length of 43 bases. Asymmetrical PCR was carried out using a forward primer modified for linear-after-the-exponential (LATE) PCR, with a primer ratio of 1:10. Approximately 500 ng total DNA (single-stranded plus double-stranded) was hybridised to each array. Results shown are mean values for duplicate spots on the same array. AA = AA mismatch between probe and PCR product, etc. B. Agarose gel electrophoresis of symmetrical and asymmetrical PCR products. The products of symmetrical and asymmetrical PCR were visualised by agarose gel electrophoresis with GelRed nucleic acid stain before and after treatment with S1 nuclease to confirm that the product of asymmetrical PCR contained single-stranded DNA (removed by S1 nuclease) as well as double-stranded DNA.