You Can Uncover Your Partner's Suspected Infidelity with DNA Testing.

Rewritten on: April 26, 2025

This article explains how to scientifically get to the bottom of suspected cheating or infidelity by your partner using DNA testing. It details the differences between semen testing, infidelity testing, and specialized infidelity testing, along with the cost and the high evidentiary value of the results.

If you want to get a clear answer about your partner's suspected infidelity, DNA testing can resolve the heavy worry you've been carrying.

Why DNA Testing Serves as Proof of Cheating or Infidelity

Some readers may still remember the infidelity scandal involving a former gravure idol that became famous through the "Womanizer" device — DNA testing was used in that very case.

DNA testing is a branch of forensic science, a technology commonly used in criminal investigations by forensic science laboratories and in paternity testing. By examining the DNA left on a sample, it identifies whose it is [ref:1]. Every person's DNA has a unique base sequence, and except for identical twins, the probability that someone else's DNA type would completely match is said to be less than one in several trillion. This overwhelming ability to identify individuals is precisely why DNA testing is recognized as having such high evidentiary value even in court [ref:2].

The Difference Between Detective Investigations and DNA Testing

When people think of investigating a cheating partner, many imagine hiring a detective. However, hiring a detective typically costs between 200,000 and 800,000 yen, with no guarantee of obtaining solid evidence. Since methods like tailing and stakeouts depend heavily on weather and the target's behavior patterns, it's not unusual for costs to balloon as the investigation drags on and needs to be repeated.

DNA testing, on the other hand, can prove that your partner and the other person were involved by identifying whose "item" the evidence of infidelity belongs to. In other words, the results of highly accurate DNA testing — the same technology used in criminal investigations — provide clearer proof of cheating than a detective ever could.

Below is a summary of the key differences between detective investigations and DNA testing.

That said, some of you may worry, "The affair partner hasn't been identified yet, so maybe DNA testing won't give us strong evidence..."

DNA Testing Is Effective Even If the Affair Partner Is Unknown

Don't worry if you don't know who the affair partner is. Simply proving that the evidence of infidelity belongs to a different man/woman — not you — is enough to establish that the affair is real. That's how strong the evidentiary power of our internationally accredited DNA testing is.

Specifically, if the DNA type extracted from bodily fluid found on bedsheets, or hair found in the bathroom, does not match the DNA type of the client or their partner, it becomes scientific proof that "a third party was present." This fact strongly supports the conclusion that the partner was intimately involved with another person, even if the identity of that other person remains unknown [ref:3].

Advanced Technology That Can Analyze Even Trace Amounts of DNA

The amount of DNA required for testing is just 1 ng (one billionth of a gram), meaning testing is possible as long as even a very small amount of DNA remains. In addition, semen testing can confirm whether a stain found on underwear or bedsheets is in fact semen.

You may understand that DNA testing is highly accurate, but still worry, "Isn't the testing cost expensive...?" Rest assured — DNA testing can resolve your worries about infidelity more cheaply and quickly than hiring a detective.

We have no confusing pricing structures or additional testing fees, so please feel at ease. We respond to your concerns and various needs at the lowest possible cost.

Why seeDNA's DNA Testing Is Chosen

• High reliability and evidentiary value as an internationally accredited institution
• Overwhelmingly lower testing costs compared to hiring a detective
• Fast turnaround, as quick as 1 to 8 business days
• Our patented "trace DNA analysis technology" can handle even damaged samples
• Free round-trip shipping for the infidelity testing kit
• Clear pricing with no additional fees
• Free retesting or partial refund guarantee if no test result can be obtained

Details of Each Testing Service

Semen Testing

Using the latest semen testing technology also used by the FBI (Federal Bureau of Investigation) and CSI (Crime Scene Investigation) units in the United States, we can accurately confirm whether a substance found on clothing or tissue paper is human male semen. Results are available in as little as 1 business day [ref:4]. Semen testing uses immunological methods such as PSA (prostate-specific antigen) testing and semenogelin testing to determine with high accuracy whether a stain is semen.

Semen Test

Infidelity Testing

Using DNA testing more precise than international standards, we can confirm whose sample was found at the scene. Results are available in as little as 6 business days. Using a technique called STR (Short Tandem Repeat) analysis, we compare the DNA type contained in a sample across multiple genetic loci to identify an individual with extremely high probability.

Specialized Infidelity Testing

Even for samples that are difficult to test with ordinary DNA testing — because they are severely damaged or were poorly stored — our patented "trace DNA analysis technology" allows us to obtain the most accurate results possible. Results are available in as little as 8 days.

Even evidence you've worked hard to obtain may have its DNA damaged or degraded by poor storage conditions, such as prolonged exposure to sunlight, in which case ordinary DNA analysis technology cannot produce results.

Specialized infidelity testing uses next-generation DNA analysis technology that can achieve a high success rate even with poorly stored samples like these. seeDNA is the only DNA testing institution in Japan that, thanks to its proprietary patented "trace DNA analysis technology," can handle analysis even with minimal DNA or DNA that has undergone mutation. Even if other testing institutions have found analysis difficult, please feel free to consult us. In the unlikely event that no result can be obtained, you may choose either a free retest using oral epithelial cells or a partial refund.

Testing Process

1. Secure the evidence of infidelity (underwear, bedsheets, tissues, hair, etc.)
2. Apply for a testing kit from the seeDNA website
3. Place the evidence and the samples of related parties (such as oral epithelial cells) into the kit that arrives
4. Return the testing kit using the enclosed return envelope (free round-trip shipping)
5. DNA extraction and analysis is carried out at the seeDNA lab
6. Results are provided in as little as 1 to 8 business days

Notes on Storing Evidence

Proper storage of evidence is extremely important for maximizing the accuracy of DNA testing. Please keep the following points in mind.

• Store evidence away from direct sunlight, in a cool, dry place
• Do not touch evidence with bare hands — use clean gloves or a cotton swab to collect samples
• Allow damp samples to air-dry naturally before mold can develop
• Keep pieces of evidence separated in individual paper envelopes or plastic bags so they don't touch each other
• Send items for testing as soon as possible (DNA may degrade further over time)

Even if the DNA has degraded due to poor storage, seeDNA's "Specialized Infidelity Testing" can still achieve a high success rate thanks to our patented trace DNA analysis technology. Even if another company has judged your sample "untestable," please feel free to consult us [ref:5].

Legal Use of DNA Test Results

DNA test results may be accepted as evidence in family court and civil court proceedings. Particularly in divorce mediation or claims for damages, they carry strong persuasive power as objective evidence grounded in science. Because the testing report issued by seeDNA is prepared under the strict quality control standards of an internationally accredited institution, it is also suitable for submission to a court.

Whereas a detective's report is limited to circumstantial evidence such as "photographs" or "records of behavior," a DNA testing report can present the undeniable physical evidence that "a specific person's DNA type was detected on the evidence" — making it extremely powerful in legal settings.

Frequently Asked Questions

Q1. Is it still evidence if DNA testing cannot identify the affair partner?

A. Yes, it is still evidence even if the affair partner cannot be identified. Simply determining that the DNA type detected on the evidence belongs to a "third party" — neither the client nor their partner — is enough to scientifically prove that the partner was intimately involved with another person.

Q2. What kinds of samples (evidence) can be submitted for DNA testing?

A. A wide range of items can be tested, including underwear, bedsheets, pillowcases, tissue paper, condoms, hair, cigarette butts, cups, and toothbrushes — anything that may carry DNA. If the evidence is too large to mail, you can rub the stained area with the dedicated cotton swab and send that instead.

Q3. Can DNA test results be used as evidence in court?

A. seeDNA conducts testing under strict quality control standards as an internationally accredited institution, and the testing reports we issue are suitable for submission to family courts and civil courts. As objective evidence grounded in science, they are recognized as having high evidentiary value.

Q4. Is DNA testing still possible if the evidence was poorly stored?

A. Even for severely damaged samples that are difficult to test with ordinary DNA testing, seeDNA's "Specialized Infidelity Testing" can achieve a high success rate thanks to our patented "trace DNA analysis technology." In the unlikely event that no result is obtained, you may choose a free retest or a partial refund.

Q5. How much does DNA testing cost?

A. seeDNA's DNA testing is overwhelmingly cheaper than typical detective fees (200,000–800,000+ yen). There are no confusing pricing structures or additional testing fees, and round-trip shipping for the infidelity testing kit is also free. The exact cost varies depending on the type of test, so please check the service page for details.

Q6. What is the difference between semen testing and infidelity testing?

A. Semen testing checks whether a stain is human male semen (results in as little as 1 business day). Infidelity testing, on the other hand, analyzes the DNA type contained in the evidence to determine "whose it is" (results in as little as 6 business days). The two are sometimes used together — first confirming whether the stain is semen, then matching the DNA type through infidelity testing.

Q7. How long does it take to receive test results?

A. Semen testing takes as little as 1 business day, infidelity testing as little as 6 business days, and specialized infidelity testing as little as 8 days. The time required may vary depending on the condition of the sample and the type of test, so please contact us for details.

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