Testing for genetic blood disorders. Researcher pipetting a blood sample from a vial. This blood sample will be tested for haemoglobinopathies, which are diseases arising from genetic defects in haemoglobin, the oxygen carrying protein in red blood cells (RBCs). Defective haemoglobin can lead to misshapen or malfunctional RBCs that cannot transport oxygen around the cell properly. Haemoglobinopathies include sickle-cell anaemia, hereditary spherocytosis, hereditary elliptocytosis and hereditary stomatocytosis. Photographed in the haemoglobinopathies laboratory at Leiden University Medical Centre, Leiden, The Netherlands.