Which of the following is a characteristic used in identification of Iodamoeba bütschlii cysts?

• A. Blunt chromatoidal bars
• B. Four nuclei with large karyosomes
• C. A well-defined glycogen mass
• D. Many ingested bacteria

Answer: (C)

The key feature used to identify Iodamoeba bütschlii cysts is a well-defined glycogen mass. In mature cysts, a large glycogen-containing inclusion fills most of the interior and is easily seen, especially after iodine staining, where it stands out as a prominent, starch-like body. This glycogen mass often pushes the single nucleus to the edge of the cyst, making it a distinctive diagnostic hallmark of this species. Other traits, such as chromatoidal bars or multiple nuclei, are more typical of other amoebae, and numerous ingested bacteria is not a characteristic feature of the cyst form in this organism.