Light Green Counterstain

Use Thermo Scientific™ Remel™ Light Green Counterstain to detect Cryptosporidium in clinical specimens.

Cryptosporidium is an intestinal protozoan parasite that causes diarrhea in animals as well as humans. This strain causes infection in immunocompromised hosts, especially those with AIDS (Acquired Immune Deficiency Syndrome)¹. A modified acid-fast stain procedure was recommended by Ma and Soave because of its simplicity and specificity to detect Cryptosporidium. Recent modification of the Kinyoun carbolfuchsin stain is recommended by Garcia for detection of Cryptosporidium oocysts in clinical specimens².

Cryptosporidium oocysts are spherical 4-6 μm in diameter, and stain pink to red to purple with Kinyoun carbolfuchsin stain. Most will contain several dark staining granules. When light green is used as a counterstain, yeast cells, which are morphologically similar to Cryptosporidium oocysts, stain green³.

Cryptosporidium is more difficult to detect in formed stool specimens. Stain time is increased that allows the oocysts to stand out from the background material. The hot acid-fast stain maximizes detection and indentification of Cryptosporidium in formed stools³.

• Easy-to-use - Examine smear in the slides mounted with mounting medium and a coverslip by bright field microscopy (40 X objective) and oil immersion is used (100 X objective) to observe the internal morphology.
• Easy-to-interpret - In case of positive test oocysts stain pink to red to purple, are 4-6 μm in diameter and round or oval in shape. One to four sporozoites maybe visible within the oocyst. In case of negative test the yeast cells and background material stain green in color.

Light Green Counterstain contains Light Green (CAS 5141-20-8), Glacial Acetic Acid (CAS 64-19-7) and Demineralized Water (CAS 7732-18-5).

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