A Staining Method for Nematodes: Determination of Nematode Resistant Stages and Direct Counts from Soil

Abstract

Because of the selectively permeable nature of nematode [Mesodiplogaster lheritieri, Acrobeloides sp. and Mononchus spp.] cuticles, staining of nematodes has been difficult. The effect of pronase and collagenase on cuticle permeability to 5 stains was discussed. Collagenase increased the rate of staining in both laboratory and field populations of dead nematodes. Live nematodes did not absorb stains even when treated with the enzymes. Nematodes must be either heat-killed or fixed in a preservative. Biebrich scarlet-eosin B, a red dye, was absorbed most rapidly, and nematodes stained were visible in soils. This allowed direct count of nematode populations in soil samples.