Shares in Bio-Rad Laboratories hit a 52-week high this week, closing Monday at $80.42, up 2.4 percent for the trading period ended Monday — a day earlier than normal due to the Thanksgiving holiday in the US this week. Stratagene led all gainers in the BCW Index with a 7.5 percent jump for the week. Qiagen led decliners for the week with a drop of 4.9 percent.