Methods and devices for thermal processing of multiple samples at the same time are disclosed. The assemblies include carriers and sample processing devices with process arrays that include conduits useful in distributing sample materials to a group pf process chambers located in fluid communication with the main conduits. The sample processing devices may include one or more of the following features in various combinations: deformable seals, process chambers connected to the main conduit by feeder conduits exiting the main conduit at offset locations, U-shaped loading chambers, and a combination of melt bonded and adhesively bonded areas. The carriers may be used to apply selective compression to the sample processing devices.