Thin Layer Chromatographic Analysis of Free Pool Amino Acids in Cercariae, Rediae, Encysted Metacercariae, and Excysted Metacercariae of Echinostoma caproni

Abstract Thin layer chromatography (TLC) was used to determine the free pool amino acid content of four larval stages (rediae, cercariae, encysted metacercariae, and excysted metacercariae) of the medically important digenetic trematode, Echinostoma caproni. These larval stages were obtained from experimentally infected Biomphalaria glabrata snails. Larvae were pooled, extracted in ethanol, and their free pool amino acids separated using four types of layers with different separation mechanisms. Zones were detected with ninhydrin spray and quantified by densitometry. Qualitative analysis revealed the presence of valine, leucine, lysine, histidine, and alanine in rediae; histidine in cercariae; histidine and alanine in encysted metacercariae; and histidine, alanine, and leucine in excysted metacercariae. Quantitative analysis showed that rediae contained 0.76 ± 0.20 ng of lysine per organism and excysted metacercariae contained 0.16 ± 0.05 ng of leucine per organism.