An organism is suitable for a GUS assay if it lacks naturally occurring β-glucuronidase activity or if the activity is very low (background activity).
ɐn ˈɔːɹɡənˌɪzəm ɪz sˈuːɾəbəl fɚɹə dʒˌiːjˌuːˈɛs ɐsˈeɪ ɪf ɪt lˈæks nˈætʃɚɹəli əkˈɜːɹɪŋ bˈeɪɾəɡlˈuːkjʊɹɹˌɑːnɪdˌeɪs æktˈɪvᵻɾi ɔːɹ ɪf ðɪ æktˈɪvᵻɾi ɪz vˈɛɹi lˈoʊ bˈækɡɹaʊnd æktˈɪvᵻɾi.