Six years after the revolutionary development of mRNA vaccines for COVID-19, 4D cellular physiologist Jennifer Lippincott-Schwartz, PhD, FAAAS, and her research team took synthetic mRNA technology to the next level. In her recent keynote talk at the 2026 American Physiological Summit in Minneapolis, Lippincott-Schwartz’s group—led by Heejun Choi, PhD—at Howard Hughes Medical Institute’s Janelia Research Campus introduced a platform to design, produce and use synthetic mRNA to study how cells are structured and work. They called this platform mRNAbow.

mRNA is short for messenger ribonucleic acid; a small genetic molecule built of nucleotides that carries instructions to make specific proteins in our cells. The cells’ nuclei produce mRNA naturally, then is delivered to the cells’ cytoplasm (its fluid-like substance) to make proteins. Once mRNA enters the cytoplasm, the cells will immediately translate the information they carry to proteins that cells will use to maintain their function.

However, it’s also possible to deliver synthetic mRNA into the cells by wrapping them in fat molecules. The easy delivery to the cytoplasm and rapid translation into proteins are major advantages of using synthetic mRNAs. We see this useful application in vaccines and cancer therapy.

Realizing the power of synthetic mRNA technology, Choi and Schwartz became curious. During COVID-19, they started to ask themselves if they could use this technology beyond therapeutics. Can scientists use synthetic mRNA to make a versatile tool that lets them see what’s going on in the cells?

Researchers today often tag proteins with a fluorescent color to study how cells work. Most of the time, scientists use viruses to deliver a genetic molecule into cells to express that fluorescent-tagged protein. However, some cell types are difficult to infect with viruses, and have low protein expression, which makes this method challenging at times.

Choi and Schwartz saw this gap and thought that synthetic mRNA could be a solution. Using COVID-19 mRNA vaccines as a kind of guide, they began to optimize a way to make a synthetic mRNA that works for most cell types. After trying multiple designs, Schwartz and her team finally found a universal design that works for different types of cells. They successfully delivered synthetic mRNA into cells without triggering an immune response and produced robust fluorescent-tagged protein expression.

The work did not stop there. Instead of using one fluorescent color tag, the research team tried four different colors—magenta, orange, green and blue—and successfully labeled four distinct cell organelles. They also painted zebrafish embryo like a rainbow with a similar approach. Thus, the mRNAbow name was born to mark this multicolor labeling ability. Lippincott-Schwartz encouraged Summit attendees to use this tool and hopes that this plug-and-play system for making versatile synthetic mRNA tool can give a robust boost to research in cellular physiology.