Removing blood sample needle. Medical worker's hands removing a needle from a patient's arm. The needle has been used to take a blood from one of the arm veins. The pad of cotton wool (white) is being used to absorb any bleeding from the vein after the needle is removed. The tourniquet at upper right was used to make the veins more visible to aid the process of taking the blood sample. The sample of blood (not seen) will be labelled and sent for testing. For the process of sampling the blood, see image M532/851.