Quick Answer: What Causes an Infidelity DNA Test to Be Inconclusive?
An infidelity DNA test may be considered inconclusive when the laboratory obtains some DNA information but not enough to confidently answer the testing question. Factors such as low DNA quantity, degraded samples, mixed DNA profiles, or incomplete genetic information can contribute to inconclusive results.
In This Article
What does inconclusive mean?
Inconclusive vs no DNA found
Common causes of inconclusive results
Can additional testing help?
How often do inconclusive results occur?
What Does "Inconclusive" Mean?
An inconclusive result means that testing produced some information, but the findings were not strong enough to reach a definitive conclusion.
Unlike a situation where no DNA is recovered, inconclusive results typically occur when:
DNA is present
testing was successful
the available information is insufficient for a clear interpretation
This means the laboratory may have recovered DNA, but additional information would be needed to confidently answer the testing question.
Inconclusive vs No DNA Found
These two outcomes are often confused.
No DNA Found
No usable DNA profile could be developed.
The laboratory was unable to recover sufficient genetic material for analysis.
Inconclusive Result
DNA was recovered and analyzed, but the findings were not strong enough to support a definitive conclusion.
This may be because the profile was too degraded or not enough alleles reached reporting the reporting threshold to be included in the results.
Learn more here: What Happens if no DNA is Found?
Common Causes of Inconclusive Results
Several factors can contribute to an inconclusive outcome.
Limited DNA Quantity
Sometimes only a small amount of DNA is present on an item.
When DNA levels are low, scientists may obtain only a partial DNA profile.
Partial profiles can limit interpretation and may not provide enough information for a definitive conclusion.
Degraded DNA
DNA naturally breaks down over time.
Factors such as:
heat
sunlight
moisture
environmental exposure
can damage genetic material and reduce the quality of the DNA profile.
Mixed DNA Profiles
One of the most common causes of inconclusive interpretation is the presence of multiple contributors.
For example, a report may indicate:
"A mixed DNA profile from a Male and Female contributor."
When multiple individuals contribute DNA to the same item, interpretation becomes more complex.
Learn more here: What Happens if Multiple DNA Profiles are Found?
Partial DNA Profiles
In some situations, scientists may recover only a portion of the genetic markers typically used for comparison.
Although a partial profile may provide useful information, it may not be sufficient for a definitive conclusion.
Can Biological Fluid Testing Still Be Helpful?
Yes.
Biological fluid testing and DNA testing answer different questions.
For example:
RSID Semen detects semenogelin
RSID Saliva detects alpha-amylase
RSID Blood detects glycophorin A
Even when DNA comparison results are inconclusive, biological fluid testing may still provide meaningful information about the presence of a particular biological substance.
Can Additional Testing Help?
In some cases, yes.
Possible options may include:
testing additional items
testing additional areas of an item
providing reference samples
performing biological fluid detection testing
in cases where male DNA may be overshadowed by female DNA a Y-STR DNA test may be more sensitive to male DNA. This may lead to a male Y-STR DNA profile being found
The best approach depends on the available evidence and the goals of testing.
How Common Are Inconclusive Results?
Most samples do not produce inconclusive results.
However, inconclusive findings can occur in real-world testing because biological evidence is often affected by:
environmental exposure
degradation
washing
multiple contributors
These factors are part of the reason why every sample is unique.
Understanding Inconclusive Results
An inconclusive infidelity DNA test result does not necessarily mean testing failed. Instead, it means that DNA evidence was recovered and analyzed, but the findings were not strong enough to support a definitive interpretation or match.
Understanding the factors that contribute to inconclusive results can help individuals better understand their reports and determine whether additional testing may be appropriate.
Related Services
Related Articles
What Happens if no DNA is Found?
What happens if multiple DNA profiles are found?
How DNA comparison testing works.
How accurate are infidelity DNA tests?
Cited References:
National Human Genome Research Institute. DNA and Genetic Analysis
https://www.genome.govNational Institute of Standards and Technology (NIST). DNA Analysis Methods
https://www.nist.gov/topics/forensic-science/dna-analysisInternational Society for Forensic Genetics (ISFG)
https://www.isfg.org
