Cryptosporidium, a protozoan belonging to the class Sporozoa, can be present in the environment as oocysts and is parasitic to cells of the digestive tract in humans and animals. In these cells, the parasite proliferates and causes severe diarrhea. Infectious oocysts are excreted in large number in feces from infected humans or animals. Human infections occur through oral transmission when contaminated food or drinking water is ingested. Oocysts in water can survive for several months under refrigeration and are highly resistant to chlorine.

BecauseCryptosporidiumcannot be cultured on artificial media, detection of the parasite is often labor-intensive. One technique for detection is to check for the presence of protozoa using fluorescence microscopy of antibody-stained oocysts. However, this technique must be performed by highly skilled and experienced technicians. This kit provides a simplified method using real-time PCR for detection of minute amounts ofCryptosporidiumin environmental samples. With this kit, the 18S rRNA gene ofCryptosporidium can be detected from both genomic DNA and cDNA reverse-transcribed from CryptosporidiumRNA. Unlike genomic DNA, RNA is known to be present at high copy number. In addition, the Crypto. Positive Control included in the kit can be used to generate a standard curve that allows quantitative determination ofCryptosporidiumcontent in samples.

This kit enables amplification products to be detected by cycling-probe technology, which provides highly sensitive detection through the combined use of an RNA-DNA chimeric probe and RNase H. This enables efficient detection of specific sequences of the gene fragment during and after amplification. One end of the probe is labeled with a fluorescent moiety and the other end with a quencher. When intact, this probe does not emit fluorescence due to the action of the quencher. However, when it forms a hybrid with the complementary sequence of an amplification product, RNase H cleaves RNA in the chimeric probe, resulting in strong fluorescent-signal emission. The amount of amplified product can be monitored by measuring the intensity of emitted fluorescence.