Smear test equipment. Close-up of a cytobrush and container of ThinPrep smear test preservation solution. The cytobrush is used to take a sample of cells from a patient's cervix (neck of the womb). The sample is then placed in a preservative solution and sent to a laboratory for examination. Abnormal cells may indicate cervical disease or cancer. Previously samples were spread straight on to a slide, but this method returns fewer contaminated or incorrect results. Cervical cancer is usually curable when detected early.