Cellular health and function, as we know today, depend on a large extent on mitochondrial function. The essential function of mitochondria is the energy production, more precisely ATP production, via oxidative phosphorylation. Mitochondrial energy production parameters therefore represent important biomarkers. Studies on human cells have mainly been performed on in vitro cell cultures. However, peripheral blood mononuclear cells (PBMCs) are particularly suitable for such examinations. That’s why this protocol describes a method to measure key parameters of mitochondrial function in freshly isolated PBMCs with the latest technology, the XF Analyzer. For this ex vivo approach PBMCs are first isolated out of human anticoagulated blood. Next, they are attached to the surface of special

Alzheimer’s Disease (AD) has long been associated with accumulation of extracellular amyloid plaques (Aβ) originating from the Amyloid Precursor Protein. Plaques have, however, been discovered in healthy individuals and not all AD brains show plaques, suggesting that extracellular Aβ aggregates may play a smaller role than anticipated. One limitation to studying Aβ peptide in vivo during disease progression is the inability to induce aggregation in a controlled manner. We developed an optogenetic method to induce Aβ aggregation and tested its biological influence in three model organisms–D. melanogaster, C. elegans and D. rerio. We generated a fluorescently labeled, optogenetic Aβ peptide that oligomerizes rapidly in vivo in the presence of blue light