Purification, quantification and mechanical hatching of eggs of the tapeworm, Hymenolepis diminuta

Eggs of Hymenolepis diminuta were separated from host's feces using a combination of NaCl flotation, filtration through nylon monofilament screen cloths, and centrifugation. The resulting purified egg preparations (PEPs) were verified microscopically to be virtually free of contaminating debris. The relationship of absorbance (500 nm) of PEPs and 'number of eggs per unit volume' was linear, and such measurements provided a rapid, reproducible method for quantifying PEPs. The average wet and dry weights of individual eggs were 2.86 x 10(-7) and 0.458 x 10(-7) g, respectively. Eggs were mechanically hatched using a Dounce homogenizer with pestle 'A'. This technique caused no detectable damage to larvae and resulted in a high percentage of 'activated' (i.e. motile) larvae.