His main research interest is developing new diagnostic approaches based on circulating DNA analysis. The applications of his inventions cover noninvasive prenatal testing, cancer diagnostics, organ transplant and autoimmune diseases monitoring. To date, he has published 169 peer-reviewed articles with a total citation of over 11,000 and an h-index of 56. He is a co-inventor of over 1,500 patent applications with over 900 granted globally covering 73 inventions on molecular diagnostics. Among his inventions, the noninvasive prenatal test for Down syndrome is the most notable. This test has been adopted in over 70 countries with millions of test performed each year.


Professor Chan also led the first large-scale prospective study to demonstrate the feasibility of using liquid biopsy to screen for early asymptomatic cancers. This work was published in the New England Journal of Medicine in 2017 and was chosen as one of the ten notable articles for that year.