Marc Quinn’s unconventional approach to portraiture has seen him replace the traditional medium of paint with human tissue. In 1991 he created ‘Self’: a three-dimensional self-portrait created from a cast of his head composed of his own frozen blood. Being the sole donor, Quinn’s blood was collected over several months to safeguard his health. The sculpture sits on a refrigerated plinth to maintain its longevity. This reliance upon technology to preserve the piece highlights the fragility of biological matter and ultimately life itself. <br><br>Quinn has since created a further five ‘blood heads’ in the series, averaging one every five years. This self-imposed documentation of Quinn’s own ageing has been likened to Rembrandt’s penchant for self- portraiture.1 In this case however, the piece not only represents the artist, it is made of him: “the ultimate portrait”.<sup>1</sup><br><br>Refrigeration is also employed to conserve Quinn’s portrait of Sir John Edward Sulston, a leading figure in the sequencing of the human genome. A sample of Sulston’s DNA was inserted into bacteria which were then allowed to develop into colonies on an agar plate. Once bacterial growth was halted an abstract, but genetically accurate, representation of Sulston remained. <br><br><br>The National Portrait Gallery in London holds a blood head within its collection as well as the portrait ‘Sir John Edward Sulston’. The inclusion of these innovative portraits by a respected art museum challenges conventional perceptions and suggests changing attitudes towards the representation of the human image. <br>