Blood fractionation is the process of separating blood into its component parts: white blood cells, red blood cells, platelets and plasma. Watch the full fourth lecture of the series: https://www.rigb.org/christmas-lectures/watch/1984/the-message-of-the-genes/bodies-and-antibodies?utm_source=youtube&utm_medium=social&utm_term=description Walter Bodmer gave the 1984 Christmas Lectures "The Message of the Genes" about how much of the variety of mankind can be explained by genetics. In the fourth lecture of the series, where this clip is from, Bodmer focuses on the human immune system, what it's made of and how it helps fights against invaders like bacteria, viruses and parasites. Watch the full series: https://www.rigb.org/christmas-lectures/watch/1984/the-message-of-the-genes?utm_source=youtube&utm_medium=social&utm_term=description The Ri is on Twitter: http://twitter.com/ri_science and Facebook: http://www.facebook.com/royalinstitution and Tumblr: http://ri-science.tumblr.com/ Our editorial policy: http://www.rigb.org/home/editorial-policy Subscribe for the latest science videos: http://bit.ly/RiNewsletter