Autolysis is a potential source of false aneuploid peaks in flow cytometric DNA histograms.

Author(s): Alanen KA, Joensuu H, Klemi PJ

Publication: Cytometry, 1989, Vol. 10, Page 417-25

PubMed ID: 2766888 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the effects of tissue type and storage at 4 degrees C or room temperature, and specimen collection method on DNA autolysis. All specimens underwent a postmortem interval of 3-33 h prior to excision of the tissue which was subsequently stored at 4 degrees C or room temperature. FNAB specimens were stored in ethanol while tissue biopsy specimens were fixed in formalin and embedded in paraffin.

   Summary of Findings:

   With storage at 4 degrees C or room temperature, a shoulder appeared on the right side of the G1 peak in some specimens by 10 h postmortem indicating DNA autolysis. Postmortem DNA autolysis proceeded the most rapidly in pancreatic specimens where false aneuploid peaks were already present after a 10 h PMI in some FFPE specimens. DNA autolysis occurred more slowly in spleen and thyroid specimens where most were unchanged after a PMI of 10 h. Liver specimens showed more rapid DNA autolysis than the spleen and thyroid, but were much better preserved after a 10 h PMI than the pancreas. The DNA indices of the false aneuploid peaks varied between 1.09-1.54 with averages of 1.17 in the FNAB group and 1.30 in the FFPE group. Intriguingly, false aneuploid peaks occurred more often in spleen, thyroid, and liver FNAB specimens compared to FFPE specimens, but less often in pancreatic FNAB specimens compared to FFPE specimens.

   Biospecimens

   • Tissue - Liver
   • Tissue - Spleen
   • Tissue - Pancreas
   • Tissue - Thyroid Gland

   Preservative Types

   • Other Preservative
   • None (Fresh)

   Diagnoses:

   • Cardiovascular Disease
   • Autopsy
   • Pneumonia/Respiratory Infection
   • Neoplastic - Other

   Platform:

   Analyte	Technology Platform
   DNA	Flow cytometry
   Morphology	H-and-E microscopy

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Preaquisition	Postmortem interval	3-10 h 14 h 22 h 33 h
   Biospecimen Acquisition	Biospecimen location	Liver Thyroid Spleen Pancreas
   Storage	Storage duration	19-38 h 46-70 h 8 days 3-10 h
   Biospecimen Preservation	Type of fixation/preservation	Refrigeration None (fresh)
   Storage	Time at room temperature	3 h 6 h 9 h 12 h 24 h 30 h 36 h 48 h 93 h 120 h 132 h
   Biospecimen Acquisition	Method of tissue acquisition	Fine needle aspiration Biopsy

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