Q10 Rule
Definition
The empirical observation that most chemical and enzymatic reaction rates roughly double for every 10-degree Celsius increase in temperature. Applied to DNA preservation: reducing storage temperature by 10 degrees approximately halves the rate of degradation reactions.
- Effect
- Reaction rate roughly doubles per 10 degree C rise
- Applies to
- Chemical and enzymatic reactions
- Forensic application
- DNA sample storage temperature planning
- Storage implication
- 10 degree C drop roughly halves degradation rate
Common questions
Why does the Q10 rule matter for biological evidence transport rather than just long-term storage?+
Evidence often sits at ambient or elevated temperature for hours during collection and transit before reaching cold storage, and the Q10 relationship means this window can contribute a disproportionate share of total degradation compared to weeks spent properly refrigerated.
Is the Q10 rule an exact figure for DNA degradation specifically?+
No. It is an approximation drawn from general reaction kinetics, and actual DNA degradation rates depend on factors like moisture, microbial load, and nuclease activity in the specific sample, so Q10 is used for planning cold-chain practice rather than as a precise predictive formula.
How does the Q10 rule justify freezing over refrigeration for long-term biological evidence storage?+
Since each further 10 degree C reduction roughly halves reaction rates, moving from refrigerator to freezer temperatures compounds into a substantial cumulative slowdown in degradation over the months or years evidence may need to be retained.
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...
- Cold Chain
- The documented, unbroken sequence of temperature-controlled environments (refrigerated vehicle, controlled intake, laboratory refrigerator or freezer) through which perishable biological evidence passes from...
- Deoxyribonuclease (DNase)
- An enzyme that cleaves the phosphodiester bonds in the DNA backbone, fragmenting double-stranded DNA into shorter pieces. Bacteria and fungi produce extracellular...
- Paper Packaging
- The standard packaging material for biological evidence. Paper is gas-permeable: residual moisture evaporates through the packaging after sealing, preventing the humid microenvironment...
- Partial DNA Profile
- A DNA profile in which results were obtained at fewer loci than the full STR panel used. Partial profiles arise from degraded...