The overall ratings of 3 Life Sciences Tools & Services stocks are down on Portfolio Grader this week. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Illumina, Inc. (ILMN) slips from a C to a D this week. Illumina, Inc. develops, manufactures and markets integrated systems for the large-scale analysis of genetic variation and biological function. For more information, get Portfolio Grader’s complete analysis of ILMN stock.

PAREXEL International Corporation (PRXL) gets weaker ratings this week as last week’s C drops to a D. PAREXEL International Corporation is a contract research and product launch organization. For more information, get Portfolio Grader’s complete analysis of PRXL stock.

INC Research Holdings, Inc. Class A’s (INCR) rating weakens this week, dropping to a D versus last week’s C. The company also gets F’s in earnings momentum. For more information, get Portfolio Grader’s complete analysis of INCR 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.