John West
Chief Executive Officer

“A Celebration of Solexa” – A Short Tour of DNA Sequencing History

By John West, CEO Personalis

On Feb 22, 2011, I went with Euan Ashley, Russ Altman, Mike Snyder and Atul Butte to sign incorporation papers for Personalis. By that point we had arranged Series A financing and were close to submitting our first publication. Since then, we’ve accomplished more than I could have imagined, through our many partnerships and collaborations that have made an impact in precision medicine. The birth of Personalis is a memorable moment, but our story arguably starts even earlier and is inextricably linked to the birth of Next Generation DNA sequencing and Solexa.

On Saturday, April 2, 2022, I was invited to a dinner at Trinity Hall in the University of Cambridge, UK. The dinner, titled “A Celebration of Solexa,” included the original scientific founders of Solexa and many of its early UK-based employees before the company became an international public company through its acquisition of Lynx Therapeutics in 2005 (Solexa was acquired by Illumina in 2007).

In attendance were two current professors from the University of Cambridge: Shankar Balasubramanian, Ph.D., and David Klenerman, Ph.D. If you have followed the history and evolution of DNA sequencing technology, you will recognize Drs. Balasubramanian and Klenerman as the two Cambridge scientists who, after a few enlightening conversations in a local pub in 1997, helped develop the sequencing by synthesis technology, or SBS, used in Illumina sequencers today. Shankar and David also founded Solexa, Ltd. in 1998 with seed funding from Abingworth Management, a UK-based venture capital company. Abingworth’s John Berriman, also in attendance at the dinner, was the original Chairman of Solexa through 2004.

From 1998 to 2001, before raising a Series A financing, the company operated from Dr. Balasubramanian’s lab at the University of Cambridge. From this lab, two budding and energetic chemists, Colin Barnes and Mark Osborne, also in attendance that night, contributed to the early development and research of Solexa.

After successful completion of the Series A round, the company moved out of Shankar’s lab to Chesterford Research Park and hired Nick McCooke as CEO and Dr. Tony Smith to lead and recruit a broader scientific team (both of whom also attended the celebration). Around this time in 2001, a Scientific Advisory Board was also formed, mostly with experts from the nearby Sanger Center (now the The Wellcome Sanger Institute, a world-leading genomics research institute). One of the original members of the advisory board in attendance that Saturday, David Bentley, went on to work as Chief Scientist at Solexa (hired by Dr. Smith in 2005) and continues in a similar role at Illumina to this day.

For my part in this tour, I worked as CEO of Solexa from 2004 to 2007, and negotiated the acquisition of the company by Illumina, then staying on as VP of the DNA sequencing business until 2008. When I first joined the company in 2004, I leveraged my previous commercial experience running the DNA sequencing business at Applied Biosystems to pivot the company’s focus from single molecule sequencing to the use of the then recently acquired DNA cluster technology (which is still the basis for Illumina sequencing systems today). In 2006, Solexa developed and shipped its first product, The Genome Analyzer, which could sequence 1 gigabase (Gb) of data in a single run (which back then was no small feat!).

Many more of the original Solexa scientists (not named above) attended the dinner celebration on April 2nd — some of whom still continue to work at Illumina. When I first joined Solexa in 2004, it had 45 employees. Today, Illumina has over 8,000 employees, and supplies most of the world’s production-scale sequencers.

Our own headquarters in Menlo Park includes multiple Illumina NovaSeq instruments in our CAP-accredited, CLIA-certified laboratory, enabling us to sequence greater than 100,000 samples per year. The story of Personalis cannot be written without acknowledging Solexa and Illumina, and this celebration was a wonderful reminder of where we’ve come from.

Colin Barnes, Nick McCooke, Shankar Balasubramanian & John West
David Klenerman & John West
Mark Osborne, Niall Gormley & Terena James
David Bentley & John Berriman
Shankar Balasubramanian (giving toast) – Tony Smith (far right)
Dinner being seated