Serotype: in the context of Adeno-associated virusesplugin-autotooltip__default plugin-autotooltip_bigAdeno-associated virus (AAV): a small eukaryotic virus that is modified and used for research and therapeutic purposes as a gene delivery vector. rAAV stands for “recombinant AAV”., a serotype is a variant of the virus with different capsidplugin-autotooltip__default plugin-autotooltip_bigCapsid: the outer shell of some viruses made from various viral proteins. proteinsplugin-autotooltip__default plugin-autotooltip_bigProtein: a molecule that is formed by the translation of messenger RNAs (mRNAs). Functions that proteins provide are what usually give organisms their phenotypes.. AAVsplugin-autotooltip__default plugin-autotooltip_bigAdeno-associated virus (AAV): a small eukaryotic virus that is modified and used for research and therapeutic purposes as a gene delivery vector. rAAV stands for “recombinant AAV”. of different serotypes can infect different cell types.