Effect of cytological fixative and environmental conditions on nuclear morphometric characteristics of squamous epithelial cells in sputum.
BACKGROUND
Sputum samples for lung cancer screening trials are typically collected at home into specimen containers prefilled with cytologic fixative. Collection, transit, and storage expose samples to environmental conditions that may introduce artifacts that could confound evaluation. We examined whether the type of cytological fixative and exposure to different environmental conditions introduces artifacts that affect cytological analysis.


METHODS
Sputum fixed in Saccomanno fluid (SAC), containing methyl, ethyl, and propyl alcohols and polyethylene glycol, or CytoRich Red solution (CRR), containing methyl and isopropyl alcohols and ethylene glycol, plus formaldehyde, was aliquoted and exposed for 8 h to the following conditions: (a) -20 degrees C freezer, (b) 60 degrees C oven, (3) direct sunlight, and (4) room temperature. Cell morphometry was evaluated using computer-assisted image analysis (CAIA).


RESULTS
The values obtained for CAIA analysis of sputum were affected by the type of fixative used. Temperature extremes and sunlight dramatically altered nuclear morphometry of SAC-fixed cells. Artifacts were not observed in CRR-fixed cells.


CONCLUSIONS
The effects of environmental exposures were minimized if sputum was placed in a formalin-containing fixative such as CRR. If an alcohol-based fixative such as SAC is used, sample handling, transport, and storage must be monitored to prevent the introduction of artifacts.
Gottschall
E Brigitte
EB
National Jewish Medical and Research Center, Denver, Colorado, USA.
McGinley
John N
JN
Spoelstra
Nicole
N
Knott
Katrina
K
Wolfe
Pamela
P
Rose
Cecile
C
Singh
Meenakshi
M
Thompson
Henry J
HJ
D002467:Cell Nucleus / Q000648:ultrastructure*; D048430:Cell Shape; D004777:Environment; D004847:Epithelial Cells / Q000166:cytology*; D005404:Fixatives; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008027:Light; D008175:Lung Neoplasms / Q000175:diagnosis; D013048:Specimen Handling / Q000379:methods*; D013183:Sputum / Q000166:cytology*; D013696:Temperature
D005404:Fixatives