1. Place sections of infected roots in 0.9% NaCl. Dissect females from roots under a dissecting microscope. Needles and a scalpel are useful tools for this.
2. Transfer the females to a small drop of 45% lactic acid in a plastic petri dish. Push a female body out of the drop in a small isthmus of lactic acid solution, so that it is held in place by surface tension.
3. Embed the end of an eye scalpel or razor blade fragment into the plastic and cut off the posterior of the nematode with a paper-cutter action.
4. Gently remove body tissue from the posterior section with a dissecting needle or nematode pick. Trim the cuticle into a square with the perineal pattern in the center.
5. Transfer the perineal pattern to a microscope slide in a small drop of glycerin. Repeat steps 1-5 so that there are several patterns (5 to 10) on the slide from the same root system. Apply a coverslip and seal.