title: Better choice of fixatives provides better histological details of the alveolar-capillary interface.
abstract: OBJECTIVE
  To evaluate lung disease, pulmonary tissues should be fixed by inflation. However, many histological sections prepared after inflation fixation show wire-like alveolar septa with capillary collapse. We investigated the reason for this artefact.
  
  
  METHODS
  To evaluate the effect of fixatives, we used the following commercially available solutions: regular 10% neutral buffered formalin (NBF), 20% NBF, 10% and 5% formalin prepared by diluting the 20% NBF, modified formalin solution as a substitute for 10% NBF, and 10% formalin prepared by diluting the 100% formalin without any buffers.
  
  
  RESULTS
  The osmolarity of the fixative was found to be responsible for the collapse artefact. Ten per cent formalin, prepared by diluting 100% formalin, the commercially available substitute for 10% NBF, and 5% formalin prepared by diluting 20% NBF, yielded the best pulmonary tissue morphology, including that of the alveolar-capillary interface.
  
  
  CONCLUSIONS
  Pulmonary physicians and pulmonary pathologists should use a suitable fixative solution for obtaining a better pulmonary architecture as well as to preserve the tissue block in optimal condition for future assessment of pulmonary diseases.
authors.affiliation: Department of Pathology, Nagasaki University Hospital, Nagasaki, Sakamoto, Japan. toma@net.nagasaki-u.ac.jp
authors.forename: Tomayoshi
authors.initials: T
authors.lastname: Hayashi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nagayasu
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kohno
authors.forename: Kuniko
authors.initials: K
authors.lastname: Abe
authors.forename: Naoe
authors.initials: N
authors.lastname: Tamaru
authors.forename: Masanobu
authors.initials: M
authors.lastname: Anami
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Sakai
authors.forename: Chiho
authors.initials: C
authors.lastname: Ohbayashi
mesh_terms: D016477:Artifacts; D002196:Capillaries / Q000473:pathology*; D005404:Fixatives / Q000737:chemistry; D005557:Formaldehyde / Q000737:chemistry; D006801:Humans; D009994:Osmolar Concentration; D011650:Pulmonary Alveoli / Q000098:blood supply*; D016707:Tissue Fixation / Q000379:methods*
chemical_list: D005404:Fixatives; D005557:Formaldehyde