A new open-access paper in Nature Communications takes a closer look at near-infrared fluorescent proteins (IFPs) as optical markers and biosensors for multi-color and thick-specimen imaging. Near-infrared light is not as strongly scattered or absorbed by biological structures as visible wavelengths, making it ideal for deep tissue and in vivo imaging of larger organisms. The authors report 3 new IFPs, validating their utility for imaging, including multi-color Structured Illumination Microscopy with Nikon’s N-SIM system.