An electrosurgical technique for the production of localized tissue ablations in the early chick embryo.

The passage of low-frequency alternating current was found superior to other methods considered for the production of small, discrete, electrolytic ablations in young chick embryos. Active electrodes of tungsten metal less than 5 /tm in diameter were prepared by controlled electrolytic corrosion. These gave reproducible, discrete foci of destruction of the required size, with currents less than 2 mA. The identification of destroyed tissue areas was immediately apparent under the operating microscope and confirmed histologically. Preliminary studies on bilateral extirpation of the ultimobranchial primordia show the absence of the ultimobranchial bodies 6 days after destruction of the primordia at 96 h of incubation.