Misha's job here at the castle was to study the chemistry of white blood cells he decided to look at the large nucleus at the center of the cell and find out what it was made of to do this he needed two things a ready supply of cells and a way of getting rid of the gloop so he could study the bare nucleus getting hold of white blood cells would normally have been tricky but tubigan was the ideal place the region had been at war with Prussia hundreds of injured Soldiers with infected wounds lay in the barracks next to the hospital their wounds were oozing copious amounts of pus which is full of white blood cells so revolting as it sounds Misha collected their old bandages so he could scrape off the pus Misha needed something else his next stop was the local slaughter house to collect a pig's stomach look here it is oh [Music] disgusting he was interested in the mucus that lined the stomach this contains an enzyme called pepsin which helps break down and digest food where where's the pepsin look here this this is the pepsin oh this sort of gloopy stuff yeah there's not much of it no that's all and this is what digests helps digest the food in the stomach yeah smells like a pig stomach to me with the pepsin Misha now had all he needed for his experiment and this is a delicacy in in tubigan yes you can um fill it with uh bread or you can cut it in stripes and then you cook it and eat it with bread is it tasty yes I'm not sure about that [Music] Misha carried the bandages and the pig's Stomach back to the lab if he was right the pepsin would break down the white blood cells then for the very first time it would be possible to examine the dense nucleus at the heart of the cell nowadays we do analysis like this using Precision equipment but of course Misha didn't have any kit like that so it wasn't easy first he had to scrape the pus from the bandages now this is mayonnaise but you get the idea then he had to wash the pepsin out of the pig's stomach using an acid and mixed it with the pus after the enzyme had done its work and digested the cells only then could he analyze the nucleus on its own [Music] now the big question was what did the nucleus consist [Music] of Misha spent months analyzing its chemistry and he found it contained a rather strange molecule this molecule was made up of carbon hydrogen oxygen and nitrogen he knew these elements were found in all living [Music] things but this molecule contained something extra phosphorus and that made it different very different it was an entirely new kind of molecule because he found it in the nucleus Misha called it nucleon we now know it as DNA [Music] intrigued Misha repeated his experiment on sperm cells from frogs carp bulls and [Music] salmon every time he found exactly the same molecule incredibly some of it has survived here in this test tube is some of the first DNA ever isolated it's DNA from salmon sperm that Misha extracted in the 1870s now it may not look like much but this brown powder marks the beginning of a scientific revolution