Free DNA in serum and plasma from normal adults.
Author(s): Steinman CR
Publication: J Clin Invest, 1975, Vol. 56, Page 512-5
PubMed ID: 1150882 PubMed Review Paper? No
Purpose of Paper
The purpose of this paper was to determine if healthy individuals have circulating DNA in plasma and serum and to compare methods of detection.
Conclusion of Paper
Circulating DNA levels in plasma were below the limit of detection for each of the 4 methods used. While the diphenylamine assay (DPA) and ethidium bromide assays (EB) failed to detect circulating DNA in serum, circulating DNA was found in serum by the more sensitive counterimmunoelectrophoresis (CIE) and RNA-DNA hybridization methods. The author notes high variability in serum circulating DNA levels by both methods. The author states that up to 2 years of frozen storage had no effect on circulating DNA levels in serum.
Studies
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Study Purpose
The purpose of this study was to determine if healthy individuals have circulating DNA in plasma and serum and to compare methods of detection. EDTA plasma and serum were obtained by centrifugation within 6 h of blood draw and were stored frozen at -20°C. 16 plasma specimens were examined by EB and RNA-DNA hybrid methods, 24 were analyzed by CIE and 27 were analyzed by DPA. 15 serum specimens were analyzed by DPA, 16 were analyzed by CIE, 5 were analyzed by EB and 9 were analyzed by RNA-DNA hybridization.
Summary of Findings:
Circulating DNA levels in plasma were below the limit of detection for each of the 4 methods used. While EB and DPA failed to detect circulating DNA in serum, use of the more sensitive CIE method resulted in circulating DNA detection in 14 of 16 serum specimens. RNA-DNA hybridization also confirmed the presence of circulating DNA in 9 of 9 serum specimens. The author notes high variability in serum circulating DNA levels. The author states that up to 2 years of frozen storage had no effect on circulating DNA levels in serum.
Biospecimens
Preservative Types
- Frozen
Diagnoses:
- Normal
Platform:
Analyte Technology Platform DNA Electrophoresis DNA Spectrophotometry DNA Fluorometry Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Aliquots and Components Blood and blood products Plasma
Serum
Spectrophotometry Specific Technology platform DPA
EB
CIE
RNA-DNA hybridization
Storage Storage conditions 0-2 years