While "T. vaginalis" does not have a cyst form, organisms can survive for up to 24 hours in urine, semen, or even water samples. A nonmotile, round, pseudocystic form with internalized flagella has been observed under unfavorable conditions. This form is generally regarded as a degenerate stage as opposed to a resistant form, although viability of pseudocystic cells has been occasionally reported. The ability to revert to trophozoite form, to reproduce and sustain infection has been described, along with a microscopic cell staining technique to visually discern this elusive form.