A sample holder for PCR processing. The sample holder includes a body with an inlet and outlet grooves formed alongside each other, a detection recess that is connected to the inlet and outlet grooves, and a fill port interconnected to both the inlet and outlet grooves, and a cover interfacing with the body to form an inlet channel interconnected to the fill port, a detection region interconnected to the inlet channel, and an outlet channel interconnected to the detection region and the fill port. The detection region is configured to receive a PCR solution from the fill port and replication occurs within the detection region via heating and cooling cycles. Thereafter, fluorescent emissions from tagged replicated DNA/RNA in the detection region are detected and measured. PCR stations, PCR station assemblies, PCR testing systems, and methods of operating a PCR testing systems are provided, as are other aspects.