Elevated Pressure Improves the Rate of Formalin Penetration while Preserving Tissue Morphology.
Formaldehyde fixation and paraffin-embedding remains the most widely used technique for processing cancer tissue specimens for pathologic examination, the study of tissue morphology, and archival preservation. However, formaldehyde penetration and fixation is a slow process, requiring a minimum of 15 hr for routine processing of pathology samples. Routinely fixed samples often have a well-fixed outer rim, with a poorly-fixed inner core of tissue. In this study, we show that the application of elevated pressure up to 15,000 psi improves the rate of formaldehyde fixation by approximately 5 to 7-fold while preserving the tissue morphology of porcine liver. The tissue also exhibited much more uniform formaldehyde penetration after 30-60 min incubation under elevated pressure than samples fixed for the same length of time at atmospheric pressure.
1. Department of Biophysics, Armed Forces Institute of Pathology, Rockville, Maryland, USA;
Ingrid E
IE
Chesnick
Jeffrey T
JT
Mason
Timothy J
TJ
O'Leary
Carol B
CB
Fowler