Roche it has extended its offer to acquire all of the outstanding common shares of Ventana Medical Systems, Inc. to 5:00 p.m. (EDT) on Thursday, August 23, 2007.

The tender offer was previously scheduled to expire at 12:00 midnight (EDT), on July 26, 2007. All other terms and conditions of the tender offer remain unchanged. As of the close of business on July 25, 2007, approximately 9936 shares have been tendered pursuant to the offer, a Roche press release stated..

On June 27, 2007, Roche commenced a tender offer to acquire all of the outstanding common shares of Ventana for $75.00 per share in cash. This price represents a 44 per cent premium to Ventana's close of $51.95 on June 22, 2007 (the last trading day prior to the announcement of Roche's offer) and a 55 per cent premium to its three-month average as of the same date of $48.30.

Greenhill & Co. and Citi are acting as financial advisors to Roche and Davis Polk & Wardwell is acting as legal counsel.

Headquartered in Basel, Switzerland, Roche is one of the world's leading research-focused healthcare groups in the fields of pharmaceuticals and diagnostics. As the world's biggest biotech company and an innovator of products and services for the early detection, prevention, diagnosis and treatment of diseases, the Group contributes on a broad range of fronts to improving people's health and quality of life.