Assembler programs have continuously improved since the first such software was written in the early 1980s. More powerful computers are also helping scientists assemble larger pieces of DNA faster than ever before. Nevertheless, even the most powerful assembly software relies more on elegance and simplicity than on brute force. A program used to assemble the human genome would fit easily on the hard disk of a typical personal computer. But you couldn't actually run the assembler from the computer on your desk.
Genome scientists venture daily into uncharted territory.
When a genome has never been sequenced before, there is nothing to tell its explorers whether they have sequenced it correctly. Some sequences are particularly difficult to copy or to sequence and get left out. But a combination of redundancy and careful checking helps ensure that errors in genome sequencing are kept to an absolute minimum. One trick for eliminating errors is to sequence the genome more than once. That way, if the sequencing machine gets a base wrong, or if a piece of DNA slips through the cracks and doesn't get sequenced, there are likely to be other, correct reads that will provide the sequence.