Microarray density continues to climb. In the past year, several companies have compressed the entire protein-coding portion of the human genome onto a single chip – that's some 30,000 to 40,000 unique gene sequences per slide. One company has reduced its arrays to the size of microtiter-plate wells, for use in high-throughput biochip analysis. And arrays to genotype 100,000 single nucleotide polymorphisms (SNPs) at once have also come to market.
"In the next few months, you're going to see more and more people doing experiments where they're interrogating the whole human genome in one experiment," predicts Gary Hardiman, director of the Biomedical Genomics Microarray Facility at the University of California, San Diego. Hardiman says human whole-genome experiments will be most useful for researchers trying to identify new biological pathways rather than for those looking in depth at smaller gene sets.
According to Mark Schena, who coauthored a seminal 1995 paper ...
