What does DNR mean on a CBC

DNR means Do Not Report. 

A CBC includes testing for WBC, RBC, Hemoglobin, Hematocrit, MCV, MCH, MCHC, RDW, Platelet Count, MPV and Differential (Absolute and Percent - Neutrophils, Lymphocytes, Monocytes, Eosinophils, and Basophils). 

However, if abnormal cells are noted on a manual review of the peripheral blood smear or if the automated differential information meets specific criteria, a full manual differential will be performed.

This means that if a certain set of results is achieved then there is no reason for further testing.