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^BMODEL RELEASED. Allergy testing.^b A skin biopsy has been taken from the forearm of a woman with a family history of allergies. The biopsy area was anaesthetised, and is receiving stitches. Another biopsy area is seen higher up on the arm. A biopsy (excision of living tissue) may be conducted after skin prick tests which help to identify allergens responsible for ^Iasthma^i or hayfever. Small amounts of various allergens are injected into the skin, and inflammation indicates an immune response. A laboratory analysis of this inflamed tissue may assist in the allergy diagnosis. The cells may also be studied genetically. Photographed at the National Heart and Lung Institute, London. (KEYSTONE/SCIENCE PHOTO LIBRARY/JAMES KING-HOLMES/SCIENCE PHOTO LIBRARY)