The ratings agency also assigned a Negative Rating Watch to the firm's notes offering, noting it will resolve this notation as more details of the offering become available.
The rating agency said it expects that the company will use the proceeds from the offering to finance its $4.2 billion acquisition of FEI.
Fitch has given the two-year senior notes offering a BBB rating with a Stable outlook.
The 10-year notes were rated BBB by Fitch, which also declared the ratings outlook Stable.
The firm plans to use the proceeds, along with cash on hand, to redeem its outstanding $1 billion senior notes that mature August 15.
The rating agency said it expects the company to use the proceeds to redeem the $1 billion principal amount of its 2.25 percent senior notes due in August.
The ratings company cited Bio-Rad's historically low leverage and low debt load, which provides a cushion against the costs associated with internal projects.
Fitch upgraded PerkinElmer's issuer default rating to BBB and cited the firm's improved operating profit and the potential for M&A.
Fitch noted Quest's leadership position in the clinical lab space and its operational improvement, but said that the company's debt leverage is elevated relative to its rating.
Fitch said the offering will temporarily raise Quest's debt leverage in 2015, but it anticipates Quest's total debt balances to be reduced by the end of the year.
Harold Varmus, a former NIH director, says that proposed reductions to the agency's budget are worrisome.
The Genome 10K project is to sequence about 10,000 vertebrate genomes, including ones of endangered species, Digital Trends reports.
The new Coalition to Save NIH Funding aims to educate lawmakers and the public on the significance of biomedical research.
In PLOS this week: analysis of viral sequences from human blood samples, gut microbiomes of heart failure patients, and more.