Lo began his research career studying
polymerase chain reaction (PCR), a
molecular biological technique for rapidly generating millions of copies of a desired
DNA sequence. He first heard about the technique at a lecture by
John Bell, now
Regius Professor of Medicine, at Oxford, and asked to learn the technique from Bell. Working with Kenneth Anthony Fleming, his future PhD advisor, Lo found the relatively new technique generated a lot of
false positives due to contamination. Lo then wondered if
fetal DNA was detectable in mother's
blood. Using PCR, he detected the
Y chromosome in a mother bearing a baby boy. During his PhD, Lo wanted to develop his research into
prenatal diagnostic test, using fetal DNA from fetal
cells in the mother's blood. This, however, was stymied by a number of factors, including low concentration of fetal cells, high false positive rate and the persistence of fetal cells after giving birth. In 1997, again using the Y chromosome as a marker in mothers bearing baby boys, Lo reported the presence of cell-free fetal DNA in most of the test subjects. This was after he read that
circulating tumor DNA were detectable in cancer patients'
blood plasma and switched strategy to search for
cell-free fetal DNA in mother's blood. One of the first disorders for which Lo developed
non-invasive prenatal testing using cell-free fetal DNA was
Rh disease, a type of
anaemia that occurs when the foetus is
Rh-positive but the mother is Rh-negative. Separately, Lo also detected fetal
RNA in mother's blood, which indicated what
genes were
expressed. He then sought novel methods to isolate fetal DNA from mother's blood, which in 2002 came in the form of difference in
DNA methylation between the mother and foetus. Lo's research into non-invasive prenatal testing was interrupted in 2003 by the
SARS outbreak. An infected patient was treated at the
Prince of Wales Hospital, the teaching hospital for
CUHK Faculty of Medicine, turning the hospital into one of the epicenters in Hong Kong. His group was one of the first to sequence the
SARS virus and to discover the existence of multiple
viral strains. Lo returned to studying detection of cell-free fetal DNA after the SARS outbreak. In 2008, he reported the use of
next-generation sequencing (NGS), which has a much higher
throughput than traditional PCR and was a relatively new technology at the time. When used to detect
Down syndrome, which is caused by an extra
chromosome 21, this method was later shown to have a 100%
sensitivity and a nearly 98%
specificity, prompting its introduction into clinics in 2011. In 2013, his group showed that the fetal
epigenome could also be determined from mother's blood plasma. Apart from non-invasive prenatal testing, Lo started investigating cancer
diagnosis, profiling and
prognosis from
circulating tumor DNA using NGS in 2012, when he reported the genetic profiling of cancer in patients' blood plasma. As of October 2021, Lo is an associate editor of
Clinical Chemistry. Lo is the co-founder of 2 biotechnology companies, both established in 2014. Using funding from the
venture capital firm Decheng Capital, he co-founded Cirina with his longtime CUHK collaborators Rossa Chiu and Allen Chan. The company focuses on cancer detection with circulating tumor DNA. The company was acquired by
GRAIL in 2017, which, in turn, was acquired by
Illumina in 2021. The 3 of them also co-founded Xcelom, which commercialised their research in non-invasive prenatal testing. In the
2021 Hong Kong legislative election, Lo was a registered elector in the
functional constituency of
Technology and Innovation and the
geographical constituency of
Kowloon West. The State Key Laboratory of Translational Oncology at CUHK, with which he is affiliated, is also a
corporate elector (an elector that is a
legal entity, as opposed to a
natural person) at the same functional constituency. As Lo is also a member of the
Election Committee of Hong Kong, making him eligible to vote in the
Election Committee constituency, he was one of the 41 voters who held 4 votes and whose voting power would be approximately 7,215 times of an ordinary citizen. and his nomination was approved unanimously on 27 September 2024. He assumed office on 8 January 2025. == Honours and awards ==