Laboratory Tests for Monitoring Chronic Lymphocytic Leukemia (CLL) The essential laboratory tests for monitoring CLL include complete blood count with differential, serum chemistry panel, and immunophenotyping, which should be performed regularly to assess disease status and guide treatment decisions. 1 A comprehensive guide to CLL testing: how doctors confirm the diagnosis using flow cytometry and analyze genetics to predict disease behavior. Confirming a correct diagnosis of chronic lymphocytic leukemia is essential before deciding on a treatment plan. The diagnosis is typically established by a blood test called flow cytometry, says Dr. Parikh. A doctor may order several tests to diagnose CLL, such as blood tests, bone marrow tests, and biopsies. The diagnosis of CLL is usually made from blood cell counts and examination of peripheral smears. Additional laboratory testing, including cytogenetic testing, molecular testing, and flow cytometry, is used in prognosis and treatment decision-making. Generally, if the red blood cells and platelets are normal, a bone marrow aspiration and biopsy are not necessary to make a diagnosis of CLL. However, these tests may be recommended before treatment begins. CLL is often found with blood tests before a person has symptoms. Tests can look at the numbers of different types of blood cells. People with CLL often have too many lymphocytes. This is a type of white blood cell. Bone marrow aspiration and/or biopsy. Blood tests and lymph node biopsies are usually enough to confirm a diagnosis of CLL, according to the ACS. However, sometimes a doctor may order imaging and genetic tests for further examination. Diagnosis of chronic lymphocytic leukemia often begins with a physical exam. The exam checks for swollen lymph nodes in the neck, underarms and groin and an enlarged spleen. Other tests and procedures include blood tests, imaging tests and taking a sample of tissue for lab testing. Blood tests or a lymph node biopsy are often enough to diagnose CLL, but if not, samples of your bone marrow might be tested.