Abstract: A flow cell subassembly includes a carriage assembly coupled to a flow cell body to selectively engage a nozzle with a base of a cuvette. The carriage assembly includes a linear bearing slidingly engaged with the flow cell body, a tiltable carriage plate coupled to the linear bearing, and a nozzle mount coupled to the tiltable carriage plate. The nozzle mount receives a nozzle assembly with the nozzle. Set screws can adjust pitch angle of the tiltable carriage plate with the linear bearing to adjust engagement between the nozzle and cuvette in a first dimension. To adjust engagement between the nozzle and cuvette in a second dimension, axial play in bolts/screws through the tiltable carriage plate into threaded holes of the linear bearing allow for yaw angle adjustments.