ILLUSTRATIONS BY JACKIE FERRENTINO
When Supratim Mukherjee noticed the same bacteriophage sequence popping up again and again in hundreds of microbial genomes from a database he was analyzing, he got excited. Mukherjee, a bioinformatician at Lawrence Berkeley National Laboratory, was comparing the metabolic pathways of the microbes, and he began to wonder what the nearly ubiquitous sequence was. “I thought we must have discovered something novel,” he recalls. “This entire bacteriophage genome was intact in all these diverse microbes.”
But when Mukherjee looked up the bacteriophage sequence, he learned that it was the sequence of PhiX, a bacteriophage sold by Illumina as part of the company’s sequencing kits to run alongside a genome of interest. Ironically, PhiX is intended as a quality-control measure, to track error rates on any ...
