Why is easy bruising so common in older adults? Most bruises form when small blood vessels (capillaries) near the skin's surface are broken by the impact of a blow or injury â often on the arms or legs. When this happens, blood leaks out of the vessels and initially appears as a black-and-blue mark. Eventually your body reabsorbs the blood, and the mark disappears.
HeLa cell. HeLa cell, a cancerous cell belonging to a strain continuously cultured since its isolation in 1951 from a patient suffering from cervical carcinoma. The designation HeLa is derived from the name of the patient, Henrietta Lacks.
Bone Marrow / Human Leukocyte Antigen (HLA) LabCorp is a leading provider of histocompatibility (human leukocyte antigen, or HLA) testing for bone marrow, other transplant-related services, and disease association testing.