title: Comparative filter techniques.
mesh_terms: D001718:Birefringence; D002482:Cellulose; D003581:Cytodiagnosis; D003937:Diagnosis, Differential; D005069:Evaluation Studies as Topic; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis; D008851:Micropore Filters / Q000592:standards; D010969:Plastics; D013183:Sputum / Q000166:cytology; D013194:Staining and Labeling; D014462:Ultrafiltration / Q000379:methods*
chemical_list: D010969:Plastics; D002482:Cellulose