[Nucleic acid and proteins content in Trypanosoma cruzi epimastigotes].

The nucleic acids and protein content in epimastigote forms of Trypanosoma cruzi during its exponential growth in vitro were studied. The parasites were cultivated in a diphasic blood-agar medium at 28 degrees C. The RNA extraction and hydrolisis were performed by the method of Fleck and Begg and the acid hydrolisis of DNA precipitate was done according to Webb and Lindstrom. Schneider's colorimetric method was used for ribose and desoxyribose measurement, employing as reagents orcein and diphenylamine respectively. Protein content was determined by the method of Lowry et al. Calf thymus DNA, yeast RNA and bovine plasma albumin were used as standards. It was established that 1.00 g of wet parasites contained 1.05 (+/-0.17) X 10(10) epimastigote forms. The contents of DNA, RNA and protein were 6.1, 12.3 and 105.4 mg/g of wet epimastigote, or 5.8, 11.7 and 100.1 X 10(-7) microgram per epimastigote, respectively. The method employed for nucleic acid determinations did not show great differences when compared with the Schmidt Thamhauser-Schneider technique, and it has the advantage of being more rapid.