Around the time hemoglitch was 12 and a half, he was simply living his normal life as a red blood cell, delivering oxygen, and even occasionally helping his friends fight bacteria
Of course, until one day, he woke up, very drowsy and confused, he saw a bunch of scientists, (who were groups of red and white blood cells) around him, they were trying to see if a red blood cell could perfectly replicate the job of a white blood cell
First off, in the cellular humor and osmosis jones universe, red blood cells can help white blood cells fight bacterium, but the scientists were trying to test that on a biological, even molecular level.
Hemoglitch then eventually tried to run, but he constantly had to hide, and eventually, he was cornered by one of the scientists, who was about to inject him with euthanasia because hemoglitch was perceived as a threat for simply trying to escape the laboratory, so, hemoglitch pushed the scientist out a window, and eventually after hemoglitch was outside the lab, one of the scientists chasing him bumped into a high pressure plasma pressure washer thing, which killed that one scientist and slices hemoglitch's head clean off, another scientist was also scared about the predicament and decided to get a cybernetic head replacement for hemoglitch, thus saving his life. So, eventually hemoglitch got some new friends, like skatez, vaxcat, apoptorrie, essentially the whole main crew.