More than 3 million samples of DNA, tissue, blood and tumour cells from willing NSW patients will be stored in the biggest biobank in the southern hemisphere designed to turbocharge medical research in the state.

The $12 million NSW Health Statewide Biobank officially opened on Monday at the Professor Marie Bashir Centre, RPA in Camperdown. It offers researchers a smorgasbord of crucial biospecimens to help better detect, diagnose and treat diseases.

Small and large-scale population studies will be able to draw on the biobank's stores to track health and disease trends including cancers, heart disease, dementia, diabetes and rare diseases over decades, and patch into international studies.

"This is going to provide the research material for almost every area of health," NSW Health Minister Brad Hazzard said of the joint initiative with the Office of Health and Medical Research and NSW Health Pathology Sydney Local Health District and Health Infrastructure.