Methods for Tattooing Xenopus laevis with a Rotary Tattoo Machine

Our research is focused on investigating the organization of the cell cortex, using Xenopus egg extracts and supported lipid bilayers. We are trying to understand how dynamic cytoskeletal patterns are regulated within the cortex and how these patterns support basic cell functions like cell division. This protocol outlines an effective and safe method for marking Xenopus laevis.

And this approach enables researchers to track genetic lines and experimental replicates and to monitor animal health. Tattooing is a cost-effective, permanent marking technique for amphibians. It's much less invasive than other permanent methods, such as skin grafts or tags.

It's also more reliable than qualitative methods, like photos or pattern recognition. To begin, connect the tattoo gun and foot pedal to the power supply. Position the foot pedal underneath the working surface.

For assembling the tattoo gun, loosen the screws in the grip with an Allen wrench. Insert the plastic tip all the way into the grip and tighten the screw to hold it in place. Then, insert the metal tube in the back of the grip to half of its length and tighten the screw while adjusting the length.

Insert a tattoo needle through the back of the grip to secure it in the plastic tip at the front of the grip. Slide the back of the needle and metal tube through the tube clamp. After adjusting the metal tube, hand tighten the tube clamp until it cannot move.

Remove the black O ring, hook the needle onto the rotor arm, and replace the O ring. Next, set the required voltage on the power supply. Once the power supply is plugged in, press the foot pedal to check if the machine works.

Fill the plastic ink pot with black tattoo ink to about three quarters full before tattooing. To begin, set up the equipment for tattooing. Place the anesthetized frog on its back on a dry unbleached paper towel.

Using a dry lint-free wipe, clear the water and mucus from the frog's chest. Then find the sternum in the center of the frog's chest with fingers, and using the non-dominant hand, hold the skin taut. Position the assembled tattoo gun vertically relative to the working surface and dip the needle into the ink.

Keeping the gun vertical, press the needle tip onto the frog's skin, followed by the foot pedal. Draw lines onto the frog's skin while applying even pressure. If the needle gets stuck, clear excess ink or skin from the needle with a wipe.

If necessary, clear excess ink on the frog's chest with frog safe water and a wipe, and then wick away moisture with a dry wipe. Continue to ink the same area until dark, legible numbers persist after wiping away excess ink. Fill a tank with 10 to 15 liters of fresh frog safe water and add a styrofoam island to provide a surface for the frog to wake up without drowning.

Wet a paper towel with frog safe water and place it flat on the styrofoam island. Next, lay the frog belly down on the towel facing the water. Fold half of the paper towel over the back half of the frog, and using cupped hands, wet its top portion.

After 24 hours, when the tattoo is healed, return the frog to its long-term housing unit. Of the frog's tattooed, 100%had visible tattoos immediately after tattooing. 100%had them 24 hours after tattooing, and 91%had them four months after tattooing.