The hatching factor of the potato-root eelworm.

1. The hatching factor of the potato-root eelworm was concentrated from potato-root leachings by adsorption on charcoal. The crude material, extracted from charcoal with acetone, was purified by partition between ethyl acetate and m-potassium dihydrogen phosphate, and ethyl acetate and a solution of potassium metabisulphite (disulphite). Neutral material was removed by extraction from phosphate buffer at pH7.8. The yield of purified material, after chromatography on silica, DEAE-cellulose and Perlon columns, was 18mug./l. of potato-root leachings, and 0.04% by weight of the acetone-soluble material extracted from charcoal; 20% of the activity of the original potato-root leachings was recovered. 2. The purified material was a colourless gum. On paper chromatograms it gave a single weakly fluorescing spot, which reacted with 2,4-dinitrophenylhydrazine and aniline-xylose reagents. It was confirmed that the hatching factor is an acid, and it is inactivated at values above pH9. Other properties were a ready oxidation by permanganate and reaction with certain carbonyl reagents. Colour tests for alpha- and beta-unsaturated gamma-lactones were negative. The hatching factor showed no light-absorption maxima at wavelengths above 210mmu; absorption bands in the infrared region (670-4000cm.(-1)) are given. Our purified material, although a gum, gave a similar hatch to a ;crystalline' product at 640 times its concentration.