Illicit drug distribution: Evaluation of DNA transfer between ziplock bags and capsules
Forensic Science International : Genetics, 2025
Authors
Journal
Forensic Science International : Genetics
Study Design
Addressed Question
how DNA from those persons involved in the manufacture, packaging and distribution of illicit drugs may accumulate on the outside of capsules and the inner and outer portions of ZLBs using simulated scenarios
Activity Context
Category
Specifications
Variables of Interest
Stringency of Control
Number of Individuals
3
Replicates per Individual and Condition
10
Nucleic Acid
Bodily Origin
Depositor & Contact
Depositor Characteristics
heavy shedder
Criteria for Shedder Status
heavy or intermediate shedder, based on P. Kanokwongnuwut et al., FSIGen 2018, Shedding light on shedders
Previous Activities
wash hands without soap for 20 seconds and wait 30 minutes, during which time they were asked to refrain from eating, wearing gloves and washing or sanitising their hands but otherwise undergo regular office activities
Contact Scenario
2-person-chain: A made and packed capsules into bags, with C being in possession of bags. 3-person chain: A made the capsules, B packed them into ZLBs, & C possessed the bags
Primary Substrate
Primary Substrate Type
capsules (gelatine)
Primary Substrate Material
Deposit
25 sec, preparation of capsules
Delay
3 days between making & packaging of capsules, 4 days RT between packaging & possession 4 days between possession & sample collection
Secondary Substrate
Secondary Substrate Type
zip-lock-bags
Secondary Substrate Material
Secondary Substrate Contact
28 sec, packaging of capsules in zip-lock-bags
Further Transfer
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Sampling
Background DNA on Sampled Surface
Sampling Time
delayed
Persistence
in total 11 days from first direct contact to sampling
Sampling Method
swabbing zip-lock-bags and capsules
Sampling Area
outside capsule, outside bag, interior zip area, inside of bag
Laboratory Analysis
Extraction
QIAGEN QIAamp® DNA Investigator Kit, 20µL elution volume
DNA Quantification
Investigator® Quantiplex Pro RGQ kit, QIAGEN™
Input for Profiling
500 pg or 17.5 µL if the DNA concentration was below 0.029 ng/µL
Profiling
VeriFiler™ Plus PCR Amplification Kit, Pro-Flex™ thermal cycler, 3500 Genetic Analyser, GeneMapper ® ID-X (version 1.4), all ThermoFisher Scientific, STRmix™ (v2.9.0, ESR, New Zealand)
Reference Samples
taken from all participants
Profile Interpretation and Mixture Analysis
STRmix™ (v2.9.0, ESR, New Zealand)
RNA Data Interpretation
n.a.
Results
DNA Quantity
2-person-chain capsules: 0.608 ng (direct), outside of bag: 0.810 ng (direct), zip area: 0.886 ng (direct), inside of bag: 0.596 ng (transfer); 3-person-chain capsules: 0.0.346 ng (direct), outside of bag: 1.836 ng (direct), zip area: 0.175 ng (direct), inside of bag: 0.596 ng (transfer),
Profile Quality
mostly full profiles
Parameter Used for Comparison
comparison to reference profile, non-exclusion/exclusion of participants determined by STRmix
Summary of Results
2-person-chain: capsules:00% major or only contributor maker (A), 70% 2-P-mixture inside of bag: 100% major or only contributor maker (A), 50% 2-P-mixture zip area: 100% included maker (A), 70% 2-P-mixture outside bag: 90% major contributor transporter (C ), 80% 3-P-mixtures; 3-person-chain: capsules: major or only contributor maker (A), no DNA from packer (B) or transporter (C) inside bag: 90% maker (A) as major of only contributor, 10% transporter (C), 80% 2-P-mixture zip area: 6/10 sampled yielded A's DNA, little DNA from packer (B), 50% transporter (C) as major, 60% 2-P-mixture outside of bag: no maker (A) DNA, little DNA from packer (B), 60% 3-P-mixtures
Raised Questions
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Cautionary Remarks
a heavy shedder was used to make and package the capsules, results may be different when an intermediate of low shedder is used