Here is a laboratory instrument that enumerates the white blood cells, red blood cells, and platelets in the peripehral blood. A "CBC" (complete blood count) is a commonly ordered laboratory test that is done on this instrument and gives important data, particularly in regard to numbers of WBC's.
Additional laboratory tests that may aid in diagnosis of an acute inflammatory process include measurement of "acute phase reactants" which are blood proteins that increase in amount, such as C-reactive protein (CRP), fibrinogen, and serum amyloid associated protein. Such proteins will increase the sedimentation rate of RBC's, which gives another non-specific indicator of inflammation - the "sed rate". Procalcitonin (PCT) can be produced by a variety of cells, including liver, kidney, pancreas, and adipose tissue. PCT can act as a cytokine in a proinflammatory response. PCT is most likely to increase with bacterial infection, but trauma may also increase PCT. Therefore, PCT is a useful marker for bacterial sepsis. None of these tests will tell you exactly where the inflammation is.