The grades of 4 Life Sciences Tools & Services stocks are on the rise this week on Portfolio Grader. Each of these stocks is rated an “A” (“strong buy”) or “B” overall (“buy”).

Charles River Laboratories International, Inc. (CRL) earns a B this week, jumping up from last week’s grade of C. Charles River Laboratories International, Inc. is a global provider of services to accelerate the drug discovery and development process. The company also gets A’s in sales growth and return on equity. For more information, get Portfolio Grader’s complete analysis of CRL stock.

The rating of Quintiles Transnational Holdings, Inc. (Q) moves up this week, rising from a C to a B. For more information, get Portfolio Grader’s complete analysis of Q stock.

NanoString Technologies, Inc. (NSTG) shows solid improvement this week. The company’s rating rises from a C to a B. The company also gets A’s in sales growth and earnings revisions. For more information, get Portfolio Grader’s complete analysis of NSTG stock.

This is a strong week for NeoGenomics, Inc. (NEO). The company’s rating climbs to B from the previous week’s C. NeoGenomics, Inc. operates a network of cancer-focused testing laboratories providing genetic and molecular testing services to hospitals, pathologists, oncologists, urologists, other clinicians and researchers, and other laboratories in the United States. The company also gets A’s in sales growth, earnings revisions, and earnings surprise. For more information, get Portfolio Grader’s complete analysis of NEO 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.