John Ugelstad (31 March 1921 – 3 April 1997) was a Norwegian chemical engineer and inventor, known for discovering a process to manufacture monodisperse micropellets or microbeads and dynabeads.

Besides teaching and research, he took on a number of assignments for industry, including being the main consultant in theoretical polymer chemistry for DuPont.

Ugelstad was already an internationally known researcher for his work in polymer chemistry when he first heard about the problem of preparing monodisperse spheres at a conference in the United States.

When he realized how easy it was to manufacture the tiny particles (15 million of them weigh a milligram, and the spheres are similar almost to microglobules in milk), he thought others would also discover the method.

The patent application concerned a method for producing polymer particles in a two-stage treatment dissolved in water, where they can absorb more than 1,000 times their own volume of water-soluble organisms.

The inquiry sparked new nights with research problems in John Ugelstad bedrooms and resulted in the development of magnetic monodisperse particles at SINTEF.

[1] Kjell Nustad and Gunnar Kvalheim, specialist physicians at the Norwegian Radium Hospital in Oslo were central to the developing the particles for medical use.

The monodisperse particles made it possible to conduct analyzes in a fraction of the time previously and produce a biological material.

The beads were absolutely indispensable in various forms of cancer treatment and important in dealing with AIDS, bacteriology and DNA technology.