Cellestis is an Australian biotechnology company that commercialises QuantiFERON diagnostic technology, a unique patented platform technology for which it has worldwide exclusive rights. Cellestis has a head office in Melbourne, Australia, with subsidiary companies in the USA and Europe, and distributors in many countries.

The first application of the technology is for the detection of tuberculosis (TB) in humans, to replace the  inaccurate and cumbersome test that has been in use for over 100 years. Cellestis' product, QuantiFERON-TB Gold , has been approved for use and sale by the US Food and Drug Administration (FDA), Japanese Ministry of Health, Labor and Welfare, Health Canada, and is CE marked for use in Europe, and is subject to recommendations for use by the US CDC, UK NICE, Japanese MHLW, and by similar bodies in many other countries.

With an estimated one third of the world's population infected with TB, the World Health Organization (WHO) declared in 1993 that tuberculosis was a "global emergency". There is a universally acknowledged need for superior and more effective early detection of TB infected people, to allow treatment before the patients develop active TB disease and spread the contagious disease to others. Thus there is an extensive international market for a new screening test.

The QuantiFERON platform technology is equally applicable to a wide range of human conditions, including other infectious diseases, as well as monitoring immune response to vaccination, cancer, and autoimmune disease. Cellestis is diversifying its QuantiFERON products to expand into these markets.