title: Rehydration of air-dried smears with normal saline. Application in fluid cytology.
abstract: Ninety fluid specimens (30 each of urine, ascitic and pleural fluid) were studied by preparing three comparable smears. One was air dried for Giemsa stain, one wet fixed in 95% ethanol and one dried on a hot plate at 37 degrees C, rehydrated in normal saline for 30 seconds and fixed in ethanol. The latter two were stained with Papanicolaou stain, and a comparison was made of the (1) retention of red blood cells, (2) retention of epithelial or mesothelial cells, and (3) cytologic preservation. The Giemsa-stained smear was used as a control for (1) and (2). Complete lysis of red blood cells was noted in the rehydration smears as compared with 70% red blood cell retention in the wet-fixed smears (P < .01). The rehydration smears retained 78% urothelial cells as compared with 55% in the wet-fixed smears (P < .01). For ascitic and pleural fluid the cell retention did not differ significantly. The wet-fixed smears scored better for overall cytologic preservation, but the difference was not significant. The rehydration smears showed a decrease in the chromaticity of staining, more flattened cell clusters and slight cell enlargement. The rehydration method was beneficial for urine and blood-stained body cavity fluids.
authors.affiliation: Department of Pathology, Caritas Medical Centre, Shamshuipo, Kowloon, Hong Kong.
authors.forename: W F
authors.initials: WF
authors.lastname: Ng
authors.forename: F B
authors.initials: FB
authors.lastname: Choi
authors.forename: L L
authors.initials: LL
authors.lastname: Cheung
authors.forename: C
authors.initials: C
authors.lastname: Wu
authors.forename: C F
authors.initials: CF
authors.lastname: Leung
authors.forename: C S
authors.initials: CS
authors.lastname: Ng
mesh_terms: D001202:Ascitic Fluid / Q000166:cytology; D003581:Cytodiagnosis / Q000379:methods*; D016591:Histocytological Preparation Techniques; D006801:Humans; D010865:Pilot Projects; D010996:Pleural Effusion / Q000166:cytology; D016707:Tissue Fixation; D014021:Tissue Preservation; D014556:Urine / Q000166:cytology