Sequential Testing Protocol
Definition
The standardised order in which biological stains are examined: presumptive test, then confirmatory test, then species confirmation, then typing and DNA analysis. Designed to answer each question using the minimum sample and the least destructive method before proceeding to the next stage.
Related terms
- Chain of Custody
- The documented chronological record of who collected, handled, transferred, and examined a piece of evidence. For digital evidence, chain of custody includes...
- Destructive Testing
- Any test that consumes, extracts, or chemically alters the stain material: cutting a fabric swatch, swabbing a surface, adding a chemical reagent....
- Differential Extraction
- A two-step DNA extraction procedure used when a stain contains both sperm cells and non-sperm epithelial cells. The first step lyses epithelial...
- Non-Destructive Examination
- Any examination that does not consume or significantly alter the stain: visual inspection, alternate light source (ALS) examination, photography, and microscopy of...
- PCR Inhibitor
- A co-extracted substance that interferes with Taq polymerase activity or primer annealing. Common inhibitors in forensic samples include haemoglobin (from blood on...
Explained in
- Order of Testing and DNA PreservationThe standardised order in which biological stains are examined: presumptive test, then confirmatory test, then species confirmation, then typing and DNA analys...