Revista do Instituto de Medicina Tropical de São Paulo
On-line version ISSN 1678-9946
MOITINHO, Maria da Luz Ribeiro and FERREIRA, Cláudio Santos. Sedimentation in parasitological coproscopy. Rev. Inst. Med. trop. S. Paulo [online]. 1992, vol.34, n.3, pp.255-258. ISSN 1678-9946. http://dx.doi.org/10.1590/S0036-46651992000300013.
A sedimentation technique is described, in which a fecal suspension is placed on top of an aqueous sucrose solution of specific gravity 1.015 g/cm3. Using 100 by 15 mm test tubes, duplicate gravity sedimentation experiments were made using homogenized fecal suspensions (single-columns) and fecal suspensions placed on top of clear columns (double-columns). Egg- and cyst-counts, and turbidity determinations were made in the sediments obtained after definite time intervals. Most Ascaris lumbricoides, Trichuris trichiura and Ancylostomidae eggs sedimented within 20 minutes in single - and between 30 and 60 minutes in double-columns. Giardia duodenalis cysts required longer periods to sediment in double - than in single-columns; after 180 minutes (the maximum period of observation), double-column sediments produced 60.0% of the counts of single-columns. Double-column sediments were consistently less turbid than single-column ones
Keywords : Parasitological coproscopy; Sedimentation techniques; LUTZ's technique.