Sirna Therapeutics( RNAI) skyrocketed on news that the San Francisco-based biotechnology company had agreed to be acquired by Merck (MRK) - Get Report in a deal worth $1.1 billion. The purchase values each share of Sirna at $13, more than double its $6.45 closing price. The stock has a 52-week high of $8.52.

Sirna is working on developing a new class of medicines based on RNA interference technology. Therapeutics of this type selectively catalyze the destruction of the RNA transcribed from an individual gene. One area in which RNA interference shows great promise is in cancer research, Merck said. Shares were soaring $5.98, or nearly 93%, to $12.43.

Intevac

(IVAC) - Get Report

gained after the Santa Clara, Calif.-based disk sputterer posted a strong third-quarter earnings report. The company made $9 million, or 41 cents a share, for the quarter ended Sept. 30, up from the year-ago $6.2 million, or 29 cents a share. Revenue rose to $54.8 million from $43.5 million a year earlier. Wall Street was looking for a 13-cent profit on sales of $45.2 million.

Equipment gross margins for the quarter rose to 42.5% from 32% a year ago, and imaging gross margins increased to 41.1% from 13.8%. Equipment margins improved primarily from lower manufacturing costs, higher average selling prices for 200 Lean systems, and higher sales of spares and upgrades. Imaging margins improved primarily as the result of favorable adjustments related to closing prior-year government rate audits and a higher percentage of revenue being derived from fully funded development contracts. Consolidated gross margins improved to 42.5% from 31.2% last year. Order backlog totaled $129.7 million on Sept. 30, compared with $96.2 million on July 1, and $65.4 million on Oct. 1, 2005. Shares climbed $4.48, or nearly 27%, to $21.32.

Blue Nile

(NILE)

lost ground after the Seattle-based online jewelry-seller saw third-quarter profit fall. Income totaled $1.8 million, or 11 cents a share, down from $2.5 million, or 13 cents a share, a year ago. The most recent quarter's results were reduced by 5 cents a share, related to stock-option expenses.

Sales increased 26.8% to $53.2 million. Wall Street was looking for earnings of 10 cents a share on revenue of $51.1 million. Looking ahead, the company said it expects full-year 2006 income to be in the range of 70 cents to 75 cents a share on sales of $249 million to $255 million. The earnings forecast includes stock-option expenses of 16 cents to 17 cents a share. Analysts are looking for income of 72 cents a share on sales of $247.9 million. Shares were trading down $1.75, or 4.5%, to $37.35.