Catholic doctrine does not treat genetic testing (DNA) as the decisive criterion for whether a relic is authentic. Instead, the Church’s discipline grounds authenticity in ecclesiastical verification, proper documentation, and sanctioned procedures—while allowing that scientific research can assist inquiry without replacing the Church’s authority and prudence.

1) What “authentic relic veneration” requires in Catholic doctrine

a) The Church requires certainty “as far as possible” and proper ecclesiastical requirements

Before anyone uses or distributes a relic, the faithful should be sure that the Church’s requirements are fulfilled and that the relic “really is, as far as it is possible for any one to know,” what it is claimed to be.1

The Baltimore Catechism also states that the Church takes “the greatest care” and requires, among other things:

• the canonization/beatification status of the person whose relic is involved must be certain;
• relics are sent in sealed packets opened only by the receiving bishop;
• each packet includes documentation proving genuineness;
• the relic cannot be exposed for public veneration until the bishop examines it and pronounces it authentic.2

b) Relics are handled under ecclesiastical authority; public cult requires a certificate

The 2017 Instruction Relics in the Church: Authenticity and Preservation reiterates that relics have received special veneration, and that relics may not be displayed for public veneration without a proper certificate of ecclesiastical authority guaranteeing authenticity.3

It further describes how authority is exercised:

• diocesan bishops and competent offices preserve relics with “special care and vigilance” to assure preservation, avoid abuses, and encourage cult properly.3

c) The Church distinguishes what counts as “significant” relics

The same Instruction distinguishes:

• significant relics: the bodies of the blessed/saints, notable parts, or ashes from cremation;
• non-significant relics: small fragments and objects that came into direct contact with the saint.3
  This matters because ecclesiastical rules and procedures apply distinctly depending on the kind of relic and the intended public veneration.3

Sources for this section: Catechism (Baltimore) on relic precautions and bishop examination; Relics in the Church Instruction on certificate/authority and types of relics.1 2 3

2) What Catholic teaching says about doubtful or controversial relics

a) There is a historical reality of doubt; the Church uses prudence

The Catholic Encyclopedia (while not a modern magisterial definition) summarizes an important prudential principle: in cases of doubtful relics, ecclesiastical authority has sometimes tolerated existing cult when people have inherited it in “perfect good faith,” and when the practical difficulty of definitive proof would cause scandal if rapidly reversed—so long as proof of spuriousness is not “so overwhelming as to amount to certainty.”4

b) Prescription/pious presumption does not override clear arguments against authenticity

Pope St. Pius X teaches a prudential standard: ancient relics retain veneration except when there are “clear arguments” showing they are false or only suppositions.5

He also emphasizes how the Church treats questionable traditions: in judgments on pious traditions, the Church uses “the greatest prudence,” and she forbids belief in matters where human arguments are not wanting—i.e., she does not simply demand credulity, but also does not let every speculation become “certainty.”5

Sources for this section: Catholic Encyclopedia summary of the Church’s prudence about doubtful relics; Pius X on prudence and “clear arguments.”4 5

3) Where genetics fits: what the Church does (and does not) claim

a) The Church’s method is authoritative verification, not laboratory reductionism

Nothing in the provided Catholic sources states that DNA/genetics is the criterion for relic authenticity. What the sources clearly require is:

• sealed handling and documentation, and
• bishop’s examination and pronouncement for public veneration.2
  And the 2017 Instruction specifies that public display requires an ecclesiastical certificate guaranteeing authenticity.3

So, even if DNA results look favorable, Catholic discipline still expects that authenticity is verified in the Church’s process, not merely “computed” from genetic matches.2 3

b) Scientific research can be pursued, but the Church’s competence is not replaced

A strong analogy from the Church’s approach to the Shroud is relevant here. Pope John Paul II explains that:

• the Church has “no specific competence” to pronounce on questions connected with the Shroud’s historical/scientific aspects; and
• she entrusts “to scientists the task of continuing to investigate” so satisfactory answers may be found.6

Even while that is about a linen relic/associated question rather than DNA of bodily remains, it illustrates the general Catholic posture: science may investigate, but the Church’s role—especially regarding public cult and certainty—remains ecclesiastical and prudential.6

c) Therefore: genetics can be evidence, not the final ecclesial “pronouncement”

Given the sources, a cautious Catholic conclusion is:

• DNA findings may serve as part of an inquiry if they help clarify identity, chain-of-custody, or exclusion of fraud—but
• the Church still requires sealed procedures, documentation, and episcopal/competent authority before public veneration.2 3
• and the Church’s doctrinal “certainty” about a relic’s authenticity is tied to ecclesiastical judgment, not merely to scientific plausibility.2 3

Because the provided sources do not explicitly address genetics, it would exceed the evidence to claim the Church has issued a direct rule like “DNA matching is sufficient” or “DNA matching is irrelevant.” What can be said with confidence from the sources is that the decisive framework is ecclesiastical.2 3

Sources for this section: Relics in the Church (certificate requirement), Baltimore Catechism (bishop examination/sealed documentation), John Paul II on Church competence vs scientific investigation for the Shroud.2 3 6

4) Abuses to avoid when scientific claims arise

a) Avoid superstition and illicit trade

The 2017 Instruction explicitly requires avoiding superstition and “illicit trade” even while relics are honored with a “religious spirit.”3

It also absolutely prohibits:

• commerce and sale of relics;
• display in profane or unauthorized places.7

So, if genetic testing becomes a sensational marketing tool (“our relic is real because DNA says so”), that would risk falling into precisely what the Church seeks to prevent: abuse and illicit trade, plus an overly superstitious framing of authentication.3 7

b) The Church’s public discipline constrains what can be taught “as certainty”

When authenticity is uncertain, the Church’s prudence described by Pius X supports restraint: relic-related matters are not treated as automatically certain merely because popular tradition exists; clear arguments against authenticity change the evaluation.5

Sources for this section: Relics in the Church Instruction on avoiding superstition/illicit trade and prohibition on commerce/sale/profane display.3 7 and Pius X on prudence about false suppositions.5

Conclusion

Catholic doctrine on relic authenticity is anchored in ecclesiastical verification: sealed transfer, documentation, and the bishop’s examination/pronouncement for public veneration.2 The Church also requires a proper certificate of ecclesiastical authority before relics may be displayed for veneration.3

In the presence of genetic findings, Catholic teaching (from the sources provided) supports the idea that science can investigate, while the Church retains responsibility for authoritative discernment and public-cult regulation—consistent with how the Church entrusts scientific inquiry about the Shroud’s historical/scientific questions to researchers without claiming specific competence to pronounce on them.6