in vitro culture and isoenzyme analysis of giardia lamblia

together with yeasts on the right arm of the tube. The motile trophozoites migrated
across its base and were isolated, free of yeast, on the left arm of the tube.
In 1976, Meyer developed a culture medium (Hanks, Serum, Phytone-1) (HSP-1)
for axenic cultivation of human isolates. One of the major components of Meyer's
medium was human serum (15-20%). Visvesvara (1980) highlighted the limitations
of using this product as batches of human serum varied in their ability to support
good growth of G.lamblia; some even inhibited growth and caused cultures to be
lost. He also recognised that G.lamblia grown in media containing human serum
(HSP-1) were unsuitable for use as antigens in serological tests because of nonspecific
staining reactions. To circumvent this, he gradually adapted the human
Giardia to grow in Diamond's Trypticase-Panmede-Serum (TPS-1) medium, which
is supplemented with bovine or rabbit sera.
A new medium, Trypticase-Yeast-lron-Serum-33 (TYI-S-33) was developed for
axenic culture of Entamoeba spp by Diamond et al. (1978) to replace the TPS-1
medium, which was at that time the most widely used for these organisms. One of
the essential ingredients of TPS-1 medium was Panmede (Paines and Byrne,
Ltd.,Greenford, Middlesex, England), a papain digest of ox liver. In time it became
increasingly difficult to obtain batches which supported good growth, hence TYI-S-
33, which is based on Trypticase, a casein digest (BBL, Cockeysville, USA) and
yeast, was developed.
Keister (1983) modified TYI-S-33 for cultivation of Giardia organisms by adding
bile and increasing the concentration of L-cysteine to the original formulation of
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