Molecular Devices ( MDCC) shares were soaring after the bioanalysis-systems maker agreed to be bought for $615 million by MDS ( MDZ), a Canada-based drugmaker. Excluding a stock option that constitutes $30 million of the total, the deal values Molecular Devices at $35.50 a share, roughly a 49% premium to Friday's $23.88 closing price. The agreement should close in the second quarter. Sunnyvale, Calif.-based Molecular Devices was adding $11.28, or 47.2%, to $35.16. MDS was up 9 cents to $17.19.

Synagro Technologies ( SYGR), which recycles organic residuals, announced that privately held Carlyle Group will buy it for $772 million, or $5.76 a share. The transaction is expected to close in the second quarter. Houston-based Synagro was trading up $1.24, or 27.7%, to $5.72.

Israel's Silicom ( SILC), which makes server-based network systems, nearly doubled its income in the fourth quarter to $1.1 million, or 20 cents a share. Sales grew 60% to $5 million. Shares were surging $2.17, or 21.7%, to $12.17.

Shares of Amcon Distributing ( DIT) jumped after the Nebraska-based company swung to a profit of $1.3 million, or $1.49 a share, in the fiscal first quarter on revenue of $209.4 million. Last year the wholesaler of cigarettes, food, and various other products lost $1.2 million, or $2.39 a share, on $198.2 million revenue. Shares were gaining $6.51, or 28.9%, to $29.01.

Origin Agritech ( SEED) tumbled after the China-based producer of hybrid crop seeds said it would take in a top line of only $80 million to $90 million in all of fiscal 2007. The analyst who follows the company is targeting $104 million, according to Thomson Financial. Shares were losing $2.59, or 23%, to $8.65.

Giga-tronics ( GIGA) increased its total year-over-year profits in the quarter ended Dec. 30 but widened its full-year losses. The Sam Ramon, Calif., testing-equipment maker said it earned $58,000, or a penny a share, nearly doubling from last year's $30,000, but flat-lining on a per-share basis. Meanwhile, year-to-date losses came to $1.4 million, or 29 cents a share, compared with a loss of only $874,000, or 18 cents a share, this time last year. Shares were down 70 cents, or 24.1%, to $2.20.