This work presents an experimental study on auto-ignition of synthetic biogas (methane/carbon dioxide mixtures). The experimental configuration consists of a fuel jet issuing into a high-turbulence, hot air co-flow to mimic conditions as those of practical devices. The study is focused on two main research aspects, instantaneous two-dimensional (2D) scalar field measurements during the onset of auto-ignition and time-resolved three-dimensional (3D) detection and tracking of auto-ignition kernels. For this purpose, advanced laser-optical diagnostics are adapted for simultaneous multi-parameter measurements.