Loaʻa ka Tf i ka plasma, ʻo ka ʻike maʻamau ma kahi o 1.20 ~ 3.25g/L. I ka poʻe olakino faeces, aneane ʻaʻohe noho. Ke hoʻokahe koko ʻana o ka digestive tract, kahe ka Tf i ka serum i loko o ka ʻōpū o ka ʻōpū a hoʻokuʻu ʻia me nā faeces, ua nui ia i nā faeces o nā maʻi kahe koko. No laila, pono a koʻikoʻi ka fecal Tf no ka ʻike ʻana i ke koko o ka ʻōpū. He ho'āʻo maʻalahi ka kit e ʻike i ka Tf i loko o nā faeces kanaka, he kiʻekiʻe ka ʻike ʻike a me ka kikoʻī ikaika. ʻO ka hoʻāʻo e pili ana i ke ʻano kiʻekiʻe specificit double antibodies sandwich reaction principle a me ke gula immunochromatographic assay analysis technics, hiki iā ia ke hāʻawi i kahi hopena i loko o 15 mau minuke.