Systems and methods for conducting designated reactions that include a fluidic network having a sample channel, a reaction chamber, and a reservoir. The sample channel is in flow communication with a sample port. The system also includes a rotary valve that has a flow channel and is configured to rotate between first and second valve positions. The flow channel fluidically couples the reaction chamber and the sample channel when the rotary valve is in the first valve position and fluidically couples the reservoir and the reaction chamber when the rotary valve is in the second valve position. A pump assembly induces a flow of a biological sample toward the reaction chamber when the rotary valve is in the first valve position and induces a flow of a reaction component from the reservoir toward the reaction chamber when the rotary valve is in the second valve position.