The invention relates to hydrocarbon pyrolysis, to equipment and materials useful for hydrocarbon pyrolysis, to processes for carrying out hydrocarbon pyrolysis, and to the use of hydrocarbon pyrolysis for. e.g., natural gas upgrading. The pyrolysis can be carried out in a reverse-flow reactor.

Methods are provided for producing a molecular array comprising a plurality of molecules immobilized to a solid substrate at a density which allows individual immobilized molecules to be individually resolved, wherein each individual molecule in the array is spatially addressable and the identity of each molecule is known or determined prior to immobilization. The use of spatially addressable low density molecular arrays in single molecule detection and analysis techniques is also provided. Novel assays and methods are also provided.