This Petri dish culture plate contained Thayer-Martin growth medium, and had been inoculated with a bacterial culture obtained from a cervical specimen, harvested from a suspected gonorrhea patient. This was the same patient whose specimen was tested in PHIL 21326 and 21327, and which had proven to be oxidase-positive. Here, however, no N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) reagent had been added to the medium, and therefore, no oxidase reaction was noted. Colonies did form on the medium’s surface, but they were merely white, pearlescent in nature. In this case, additional tests would still have to be conducted, in order to definitively prove the presence of Neisseria gonorrhoeae bacteria.