The grades of three life science stocks are on the rise this week on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

This week, Quintiles Transnational Holdings, Inc. (Q) is showing significant improvement as the company’s rating hops from a C (“hold”) to a B (“buy”). In Portfolio Grader’s specific subcategories of Earnings Growth, Earnings Momentum, Earnings Revisions, Earnings Surprise and Margin Growth, Q also gets A’s. For more information, get Portfolio Grader’s complete analysis of Q stock.

This week, Covance (CVD) is showing good progress as the company’s rating jumps from a B (“buy”) last week to an A (“strong buy”). Covance is a drug development services company providing a range of early-stage and late-stage product development services to the pharmaceutical, biotechnology, and medical device industries. For more information, get Portfolio Grader’s complete analysis of CVD stock.

Albany Molecular Research, Inc. (AMRI) earns a B this week, jumping up from last week’s grade of C. Albany Molecular Research provides contract services to various pharmaceutical and biotechnology companies primarily in the United States, Europe, and Asia. For more information, get Portfolio Grader’s complete analysis of AMRI stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.