The Nanoparticles
The nanoparticles are made out of gelatin. This kind of nanoparticles has been shown to be able to transport proteins, organic molecules or DNA. They were biotinylated using activated biotin. We invite you to read more about Nanoparticles. To assemble the nanoparticles with the bacteria, they only need to be in the same tube, because the interaction between biotin and streptavidin is very strong and spontaneous.