DNA extraction. Source: Flickr.com

The first time I encounter DNA block copolymer (see this on my old blog), I did not read the experimental section and took it for granted that the ssDNA sequences be synthesized by PCR. As the field of DNA as a polymer is growing I become confused why the molecular biologists who are familiar with PCR get into what should be the interest of a chemist – self-assembly based on well-defined building block. DNA block copolymers have raised the interest of chemists in the fields of block copolymer and self-assembly, but they need additional PCR machines, electrophoresis gels and the corresponding techniques to try their first DNA block copolymer out, which are out of the reasonable range of equipments in a chemistry lab.

I was wrong, however, because previous studies did not employ PCR for their DNA part of synthesis and the lengths of nucleic-acid segment were indeed restricted, until now. A recent communication published on Adv. Mater. (2007. DOI: 10.1002/adma.200700240) described a technique to construct various forms of DNA block copolymer with synthetic block via PCR. Di- and triblock copolymer with different block compositions can be obtained by carefully designing the primer. Products are purified and characterized by agarose gel. PCR allows longer DNA sequence to be incorporated in to synthetic block copolymers.

DNA has shown its promise in molecular device (switches, motors, and tweezers) and self-assembly (nanoparticles and micelles). Chemistry labs which intent to join this field should recruit student with biological background and buy some PCR and electrophoresis devices as soon as possible.