The use of fresh-frozen tissue in diagnostic transmission electron microscopy.

Author(s): McGinley DM, Posalaky Z, Posalaky IP

Publication: Ultrastruct Pathol, 1984, Vol. 6, Page 89-98

PubMed ID: 6730027 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine if tissue ultrastructure is adequately preserved by freezing specimens either in a cryostat (-20 degrees C) or by immersion in isopentane pre-cooled with liquid nitrogen (-155 degrees C). A total of 11 cases were examined using specimens collected from kidney, skeletal muscle, salivary gland, skin, lymph node, pituitary gland, breast, peritoneum, and prostate. Specimens were embedded in OCT and frozen in a -20 degree C cryostat for 15-30 min or immersed in isopentane that was pre-cooled with liquid nitrogen before sectioning, post-fixation in Karnovsky's fixative at 4 degrees C, and analysis by TEM. With the exception of a single kidney specimen that was divided and preserved by snap-freezing in isopentane and immersion in glutaraldehyde, specimens were not matched for case or tissue type.

   Summary of Findings:

   Minimal ultrastructural damage associated with nuclear ice crystal formation was noted among specimens frozen in OCT in a -20 degrees C cryostat. However, the ultrastructure of specimens embedded in OCT and frozen in isopentane that had been pre-cooled with liquid nitrogen were remarkably consistent with case-matched controls fixed in glutaraldehyde. The authors conclude that organelles could be reliably identified for both cryopreservation methods when post-fixed in Karnovsky's fixative prior to TEM processing, and tissue preserved by both methods holds diagnostic value, despite some freeze-induced artifacts.

   Biospecimens

   • Tissue - Kidney
   • Tissue - Salivary Gland
   • Tissue - Skin
   • Tissue - Muscle (Skeletal)
   • Tissue - Lymph Node
   • Tissue - Pituitary Gland
   • Tissue - Breast
   • Tissue - Prostate
   • Tissue - Other

   Preservative Types

   • OCT
   • Other Preservative

   Diagnoses:

   • Neoplastic - Carcinoma
   • Neoplastic - Benign

   Platform:

   Analyte	Technology Platform
   Morphology	Ultrastructure

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Preservation	Cooling or freezing method/ rate	Cryostat (-20 or -30 degrees C) Pre-cooled isopentane
   Biospecimen Preservation	Type of fixation/preservation	Glutaraldehyde OCT

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