A method is described for staining lipid in fourth-stage dispersal juv
enile nematodes fixed with formal-acetic fixative (FA4:1). Bursaphelen
chus xylophilus fourth-stage dispersal juveniles were fixed with hot F
A4:1 for 24 hours, excess fixative was removed, and a solution of satu
rated oil red O in 96% ethanol added and allowed to sit for 25 minutes
at 60 C. Excess oil red O was removed, nematodes were washed twice wi
th 70% ethanol, and were processed to pure glycerin. Lipid droplets wi
thin the nematodes were viewed by light microscopy and appeared as dar
k red spheres of various sizes. Computerized image analysis was used t
o quantify lipid droplet area.