High resolution fluorescence microscopy evidence on the transport of immunoglobulins. Differences between mammalian IgG, F(abʹ)2 and avian IgY

► We studied the subcelular distribution of IgY, F(abʹ)2 and IgG injected I.V. in mice. ► The Igs were labeled with fluorescein isotiocyanate and observed with deconvolution fluorescence microscopy. ► IgG and its F(abʹ)2 have a sub-cellular distribution very different from IgY. ► The Igs seem to pass kidney glomeruli but only IgG and F(abʹ)2 seem completely reabsorbed in nephrons. ► Our result that pharmacokinetics for IgG and F(abʹ)2 are very different of IgY PK.