Metagenomics
Definition
The direct sequencing of all DNA extracted from an environmental sample, bypassing the need to culture individual organisms. It produces a community-wide genetic profile that can be searched against reference databases to identify constituent species and their relative abundances.
Related terms
- 16S rRNA Amplicon Sequencing
- A targeted sequencing approach that amplifies a variable region of the bacterial 16S ribosomal RNA gene, which acts as a universal phylogenetic...
- Cadaver Decomposition Island (CDI)
- The localised area of soil and vegetation altered by the decomposition fluids and gases released from a body. A CDI has a...
- Collagen Peptide Barcoding
- Species identification from trypsin-digested collagen analysed by mass spectrometry. Peptide sequences differ between species at diagnostic positions that survive tanning and heat...
- DNA Fragmentation
- Physical breakage of the DNA backbone into short pieces. In degraded samples the average fragment length may be 50-200 bp, making long...
- Library Preparation (aDNA)
- Enzymatic end-repair, adapter ligation, and amplification of all DNA fragments in a sample regardless of length, used in ancient-DNA and degraded-sample workflows....
- 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...
- Post-Mortem Interval (PMI)
- The time elapsed between death and discovery or examination of remains. PMI estimation draws on multiple disciplines: soft tissue decomposition stage, insect...
- Short-Amplicon Strategy
- A PCR design that targets the shortest possible fragment length: often 80-150 bp: within a diagnostic locus such as COI. Shorter targets...
- Soil Microbiome
- The total community of microorganisms inhabiting a soil sample. Each location has a characteristic baseline community shaped by climate, vegetation, and soil...
- Thanatomicrobiome
- The community of microorganisms that colonise a body after death, arising primarily from gut bacteria that breach the intestinal wall and spread...
Explained in these topics
- DNA from Degraded and Processed Wildlife ProductsShotgun sequencing of all DNA in a sample followed by bioinformatic assignment of reads to taxa. Does not require prior knowledge of which species are present;...
- Microbial and Microbiome Evidence in Forensic CasesThe direct sequencing of all DNA extracted from an environmental sample, bypassing the need to culture individual organisms. It produces a community-wide genet...