Provided are systems for biological sample processing and analysis. A system can comprise a substrate configured to rotate. The substrate can comprise an array configured to immobilize a biological analyte. A fluid flow unit comprising a fluid channel can be configured to dispense a solution comprising a plurality of probes. The solution may be directed, via centrifugal force, across the substrate during rotation of the substrate, to couple at least one of the plurality of probes with the biological analyte. A detector in optical communication with the array can be configured to detect one or more signals from the at least one probe coupled to the biological analyte.