Archival Notice
This is an archive page that is no longer being updated. It may contain outdated information and links may no longer function as originally intended.
Home | Glossary | Resources | Help | Contact Us | Course Map
Step One: Solubilization of Stain Components
Water must be replaced so that dried stains can be resolubilized for DNA extraction procedures. The DNA is protected from unnecessary degradation in this process by adding EDTA, a magnesium chelator, to the lysis buffer. EDTA prevents nucleases from degrading the DNA. Tris (a component of the buffer) interacts with the lipopolysaccharides present on the outer cell membrane, which helps to make it permeable. This effect is enhanced with the addition of EDTA.06
Step One Reagents
Stain extraction buffers are usually slightly alkaline and generally contain Tris base or Tris-HCl (pH between 7.5-8.0), EDTA, and sodium chloride (NaCl).
Additional Online Courses
- What Every First Responding Officer Should Know About DNA Evidence
- Collecting DNA Evidence at Property Crime Scenes
- DNA – A Prosecutor’s Practice Notebook
- Crime Scene and DNA Basics
- Laboratory Safety Programs
- DNA Amplification
- Population Genetics and Statistics
- Non-STR DNA Markers: SNPs, Y-STRs, LCN and mtDNA
- Firearms Examiner Training
- Forensic DNA Education for Law Enforcement Decisionmakers
- What Every Investigator and Evidence Technician Should Know About DNA Evidence
- Principles of Forensic DNA for Officers of the Court
- Law 101: Legal Guide for the Forensic Expert
- Laboratory Orientation and Testing of Body Fluids and Tissues
- DNA Extraction and Quantitation
- STR Data Analysis and Interpretation
- Communication Skills, Report Writing, and Courtroom Testimony
- Español for Law Enforcement
- Amplified DNA Product Separation for Forensic Analysts