The ratings of 4 Life Sciences Tools & Services stocks are down this week, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

QIAGEN NV (QGEN) is having a tough week. The company’s rating falls from a C to a D. QIAGEN NV provides sample and assay technologies. For more information, get Portfolio Grader’s complete analysis of QGEN stock.

This week, Albany Molecular Research, Inc.’s (AMRI) rating worsens to a D from the company’s C rating a week ago. Albany Molecular Research, Inc. provides contract services to various pharmaceutical and biotechnology companies primarily in the United States, Europe, and Asia. The company also gets F’s in operating margin growth. For more information, get Portfolio Grader’s complete analysis of AMRI stock.

This week, Accelerate Diagnostics, Inc. (AXDX) drops from a C to a D rating. Accelerate Diagnostics, Inc. develops diagnostic systems for bacterial infections. The company also gets F’s in return on equity. For more information, get Portfolio Grader’s complete analysis of AXDX stock.

Genetic Technologies Limited Sponsored ADR’s (GENE) rating weakens this week, dropping to a D versus last week’s C. Genetic Technologies Limited Sponsored ADR is a biotechnology company that practices advanced DNA genetic research and testing. The company also gets F’s in sales growth, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of GENE 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.