Gerry Baker is Editor at Large of The Wall Street Journal. His weekly column for the editorial page, “Free Expression,” appears in The Wall Street Journal each Tuesday. He is also host of the weekly ...

Editor's Note: APYs listed in this article are up-to-date as of the time of publication. They may fluctuate (up or down) as the Fed rate changes. CNBC Select will update as changes are made public.

Expression systems are genetic constructs (a gene encoded by DNA) that are designed to produce a protein, or an RNA (ribonucleic acid), either inside or outside a cell. Expression systems are used in ...