Bits of DNA were assembled and spliced together to make the genome of a virus called Phi-X - which normally infects bacteria. The man behind the work is Craig Venter, hailed as a pioneer in reading the human genetic code. The work is published in the Proceedings of the National Academy of Science in the United States. Craig Venter has artificially constructed the genetic blueprint of a virus from scratch using bits of DNA. The virus, known as Phi-X174 (Phi-X), usually infects bacteria. It was the first organism to have its genetic code read. Its genome consists of 5386 segments of DNA arranged in a small circle. Previously, other researchers have synthesised the poliovirus genome using enzymes that naturally occur in cells. However, that effort took years to achieve and produced viruses with defects in their synthesised genetic code. In an effort to improve the speed and accuracy of this genomic synthesis, Craig Venter and colleagues from the Institute for Biological Energy Alternatives, have adapted a frequently used technique - the polymerase chain reaction (PCR) into one called the polymerase cycle assembly (PCA) - to reconstruct the genome of Phi-X. PCA is a technique that produces double-stranded copies of gene sequences, ideal for assembling a genome.