Therefore, our aim was to establish 89Zr radiochemistry for brain application by performing ex vivo and in vivo biodistribution studies of a bispecific anti-amyloid-beta aducanumab derivate mAbAdu-scFab8D3 (Adu-8D3), in an APP/PS1 mouse model of Alzheimer's Disease. The gene discussed is APP; the disease is early-onset autosomal dominant Alzheimer disease.