Focal electroporation in ovo

Gene expression fields in embryogenesis are spatially precise and often small, so experimental gene expression often requires similar spatial definition. For in ovo electroporation, typically a gene construct is injected into a natural body cavity in the embryo prior to electroporation. Limited control of the size and location of the electroporated field can be obtained by varying electrode placement and geometry, and by altering the miscibility and viscosity of the construct vehicle but it is difficult to tightly constrain electroporation to small regions. Electroporation of different constructs in close proximity has not been possible. We show that loading the construct into an agarose bead, which is then microsurgically implanted, allows for focal electroporation. Different constructs can be electroporated in close proximity by emplacing several agarose beads. This technique is simple, cheap, rapid, and requires no more specialised equipment than that required for conventional in ovo electroporation. Developmental Dynamics 238:3152–3155, 2009. © 2009 Wiley‐Liss, Inc.