Abstract: An example system includes a detector configured to detect a value that is based on a hematocrit of a test sample containing plasma and red blood cells, a fluidic channel configured to hold the test sample, and an acoustic transducer configured to apply acoustic waves to the fluidic channel to separate the plasma from the red blood cells in the fluidic channel. The acoustic waves have at least one of an amplitude, a frequency, or a duration that is based on the value.