Flow cytometry approaches combined with a genetically encoded targeted fluorescent biosensor are used to determine the subcellular compartmental availability of the oxidized form of nicotinamide adenine dinucleotide (NAD+). The availability of free NAD+ can affect the activities of NAD+-consuming enzymes such as sirtuin, PARP/ARTD, and cyclic ADPR-hydrolase family members. Many methods for measuring the NAD+ available to these enzymes are limited because they cannot determine free NAD+ as it exists in various subcellular compartments distinctly from bound NAD+ or NADH. Here, an approach to express the sensor in mammalian cells, monitor NAD+-dependent fluorescence intensity changes using flow cytometry approaches, and analyze data obtained is described. The benefit of flow cytometry approaches with the NAD+ sensor is the ability to monitor compartmentalized free NAD+ fluctuations simultaneously within many cells, which greatly facilitates analyses and calibration.
- circularly permutated fluorescent protein
- fluorescent sensor
- genetically encoded biosensor
- nicotinamide adenine dinucleotide
ASJC Scopus subject areas
- Medical Laboratory Technology