Quantification of RNA degradation by semi-quantitative duplex and competitive RT-PCR: a possible indicator of the age of bloodstains?
Author(s): Bauer M, Polzin S, Patzelt D
Publication: Forensic Sci Int, 2003, Vol. 138, Page 94-103
PubMed ID: 14642725 PubMed Review Paper? No
Purpose of Paper
Conclusion of Paper
Studies
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Study Purpose
The purpose of this study was to determine the effects of sunlight, humidity, temperature, collection into EDTA, and storage duration on RNA degradation in dried bloodstain specimens. RNA degradation was measured by semi-quantitative duplex RT-PCR in combination with competitive RT-PCR with an external standard and laser-induced fluorescent capillary electrophoresis.
Summary of Findings:
RNA suitable for RT-PCR was obtained from dried bloodstains after up to 15 years of room temperature storage when protected from sunlight. However, RNA degradation levels increased with storage time. Specimens stored for less than 2 years required fewer cycles (25 vs. 30) to reach the exponential phase of PCR amplification. Exposure to 2 months of sunlight had no significant effects on RNA degradation when compared to specimens protected from sunlight for 1 and 3 months. RNA degradation was also similar in EDTA-specimens stored for 2 years and EDTA-free specimens stored for 20 or 30 months. No RNA suitable for RT-PCR could be extracted from dried blood specimens stored at 37 degrees C and 100% humidity for 1 week.
Biospecimens
Preservative Types
- None (Fresh)
Diagnoses:
- Normal
Platform:
Analyte Technology Platform RNA RT-PCR Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Storage Time at room temperature 20 months
24 months
30 months
41 months
49 months
59 months
96 months
180 months
0 weeks
1 week
1 month
2 months
3 months
6 months
8 months
13 months
Storage Storage conditions Protected from sunlight
Exposed to sunlight
37 degrees C and 100% humidity
Biospecimen Acquisition Anticoagulant EDTA
None
RT-PCR Specific Targeted nucleic acid Beta-actin
Cyclophilin