Separation of large and small granules from horseshoe crab (Tachypleus tridentatus) hemocytes and characterization of their components.

We designed a method for separating two types of granules, a smaller (S) but dense and a larger (L) but less dense granule from hemocytes of the horseshoe crab (Tachypleus tridentatus), using continuous sucrose density gradient centrifugation. The isolated L-granules contained at least three clotting factors plus a clottable protein, coagulogen, as the major component. The known anti-lipopolysaccharide factor and 7 additional unknown protein components were also present in the L-granules.