① The yolk plant hemisphere is removed to form an axonless embryo or to suppress the egg yolk movement of the goldfish. In the former case, resection should be terminated at 1-2 cell stage. Immediately after fertilization, the egg membrane is removed and begins as soon as the direction of the blastoderm is known. In the latter case, it can be done at any time after the 32-cell phase, but it is easier to do it after the MBT.
② Put the primary culture in an agarose petri dish (softer, about 0.8%) and line up the egg membrane-removed eggs.
③ Move the egg with the operating needle so that the animal and vegetable poles can be seen.
④ Lightly apply the glass wool of the surgical needle to the side of the egg and gently push it.
⑤ Then slowly press the glass wool down to the side of the agarose.
⑥ When glass wool is attached to the agarose surface, slowly and finely move glass wool in its axial direction.
⑦ Even if the yolk begins to break, continue moving it without stopping, and do not stop until it is finally severed.
⑧ Collect only the hemisphere on the animal pole side.
