0. Introduction

UPDATE: See also my reply to Dr. Maxime Georgel. I further develop the arguments that are presented here and respond to a number of objections that are not addressed in this post.

This is the second installment in a series of articles surveying the evidence for Catholic miracles. My objective is to present the miracle case for Catholicism in a way that is rigorous enough to persuade those that are strongly predisposed towards skepticism. That means empirical data has to be inferred from primary sources and every skeptical explanation has to be excluded by multiple lines of evidence.

In this article, I focus on the evidence for the Eucharistic Miracle of Lanciano. In the first section, I argue that the Lanciano relics consist of human cardiac tissue and blood clots. In the second section, I argue that skeptical explanations of the origination of the relics are not tenable. In the third section, I argue that skeptical explanations of the preservation of the relics are not tenable either. In the fourth section, I conclude the best explanation is that Lanciano was divine vindication of Catholicism. In the fifth section, I respond to objections to that conclusion.

1. Identification

For centuries, the Lanciano relics have been venerated as the remains of a Eucharistic miracle, believed to have taken place when a doubting priest witnessed the elements transform during Mass. In 1886, the relics were secured with episcopal seals. When the Archbishop of Lanciano authorized a scientific investigation in 1970, the seals were broken in the presence of church officials, and Professor Odoardo Linoli was permitted to extract fragments of the relics. After a thorough investigation, Linoli concluded the ‘flesh’ was human cardiac tissue and the ‘blood’ was human blood.1

Linoli was the Head of the Laboratory of Clinical Analysis and Pathological Anatomy at the Hospital of Arezzo in Tuscany, Italy.2 In other words, he was in charge of quality control for clinical diagnostic science at a mid-sized teaching hospital. That means he had continuous, high volume, hands-on experience with histopathology, serology, and chemical assays. It also means he was attuned to all of the procedural and interpretative errors that can lead to misidentification of samples. Furthermore, Linoli was certified to teach anatomy, histology, clinical microscopy, and chemistry to medical students and young doctors.3 It is indisputable that he was unusually qualified to determine whether the Lanciano relics were human flesh and blood.

To strengthen the credibility of his findings, Linoli solicited the opinion of an independent expert, Professor Ruggero Bertelli. At the time, Bertelli was an emeritus professor of human anatomy at the University of Siena, one of Italy’s top secular universities. Linoli gave Bertelli a series of histological preparations. After carefully examining those slides, Bertelli concurred with Linoli’s identification.4 Linoli published his findings in a scholarly journal.5 In 1981, Professor Linoli carried out a supplemental investigation at the request of the Friars Minor Conventual, this time on a leftover sample. The results of the follow-up study were even more conclusive than the original results, since the newly examined fragment possessed evidentially significant features that had not been apparent in the previously examined fragment.6

1.1 - Gross anatomy

Macroscopically, the ‘flesh’ has the morphology of desiccated cardiac tissue.7

• (Consistency) Uniformly hard, ligneous, resistant to cutting. When animal tissue desiccates, it collapses into a dense, fibrous mass with a woody feel. Fibrous, woody consistency excludes bread, which crumbles, plant matter, which becomes brittle and splinters, and inorganic matter, which fractures in crystalline patterns.

• (Geometry) Circular disc, ~55 mm in diameter. The dimensions of the relic are consistent with the left ventricle of an adult male. The combination of a rounded perimeter and a concentric void is diagnostic of tissue derived from a hollow, chambered organ. Solid organs do not exhibit a central opening when sectioned.

• (Thickness) Marked peripheral thickness, progressive thinning towards the center. That is consistent with a laminar section oriented tangentially to the local surface across the full width of an ellipsoid, in which less material is intersected near the point of tangency and more is intersected towards the periphery.

• (Protrusion) A discrete, localized protrusion extends into the central void and remains continuous with the surrounding mass. That is suggestive of the heart rather than a generic hollow viscus, since intraluminal muscular projections form singular, nodular relief within the otherwise smooth chambers of ventricles.

1.2 - Histology

Microscopically, the ‘flesh’ has the morphology of desiccated cardiac tissue.8

• (Fiber morphology) Fibers have unequal, modest lengths, nearly uniform thickness, and are gathered in bundles of varying sizes. Higher magnifications reveal a longitudinal fibrillar structure. Those features confirm striated muscle.

• (Syncytial aggregation) Fibers branch and join end-to-end, with occasional transverse bridges, forming a pervasive interconnected network. That architecture—a universal aspect of the tissue—is diagnostically specific to myocardium.

• (Adipose interdigitation) A lobule of adipose tissue in the interstitium is crossed by muscle fibers that branch within it, dispersing and ending among lipocytes. That reinforces the cardiac, as opposed to skeletal, identification of the tissue.

• (Endocardial layer) A continuous fibrous lamina with a rough, papillary-like surface overlies subendocardial tissue containing vessels, with syncytial myocardium beneath, matching the structure of ventricular endocardium.

1.3 - Uhlenhuth test

Linoli performed the Uhlenhuth test on eluates from both the ‘flesh’ and the ‘blood.’ He used commercial anti-human protein serum from the reputable supplier Behringwerke, and ran the reaction in parallel with controls: rabbit serum, bovine serum, and saline.9 In the 1960s-70s, Behringwerke was selling forensic-grade antisera that were specifically marketed for medico-legal use, where cross-reactivity would have undermined their admissibility. The standard practice among commercial suppliers at that time was removal of heterospecific antibodies by absorption and validation tests against panels of domestic animal species.10

The results were unambiguous: both the ‘flesh’ and the ‘blood’ produced a clear precipitin band within about five minutes with human antiserum, while no reaction appeared in the animal or saline controls.11 In forensic science, the combination of a rapid, strong positive in the target antiserum and complete negativity in animal controls is decisive evidence of a true homologous match.12 Weak cross-reactions with domestic animals can sometimes occur with low-quality antisera, but these develop slowly and faintly. The speed and clarity of Linoli’s reactions, coupled with the absence of any band in the controls, is inconsistent with a cross-reaction.13

1.4 - Absorption–elution test

Linoli performed the absorption–elution test on eluates from both the ‘flesh’ and the ‘blood.’ Both eluates reacted with anti-A and anti-B antisera, indicating that they belong to blood group AB. To ensure these reactions were not caused by nonspecific background effects, Linoli included substrate controls made from blotting paper that had never come into contact with the samples, which produced no agglutination. He also determined that his samples were unlikely to be explained by adventitious contamination. In 1991, the AB result was reproduced by the University of Siena.14

1.5 - Thin-layer chromatography

Linoli performed thin-layer chromatography on an alkaline extract of the ‘blood.’ In triplicate runs, the migration of the extract was perfectly aligned with oxyhemoglobin and alkaline hematin standards, demonstrating the presence of heme-derived compounds in the sample. Teichmann and Takayama tests came back negative, indicating that the hemoglobin was too degraded to produce crystals. Regardless, degraded hemoglobin is decisive evidence that the ‘blood’ is genuine blood.15

1.6 - Protein electrophoresis

Linoli examined the protein profile of the ‘blood’ using cellulose acetate electrophoresis. The electrophoretic tracing showed a regular distribution of serum protein fractions, matching the pattern of human blood serum. Linoli emphasized that the sequence and proportions of the fractions were “completely regular and comparable to that of fresh serum,” confirming the eluate retained the profile of human serum despite its antiquity. The values were most consistent with the blood serum of humans as opposed to the blood serum of common domestic animals.16

2. Origination

2.1 - Provenance

When inquiring into the origins of the Lanciano relics, the first question is chronological: what is the latest date they could have emerged? To answer this, we need to trace the documentary evidence for the relics, working backwards.

From the seventeenth century onward, the chain of custody is secure. First, we know from episcopal visitation records and devotional accounts that the Church was continuously exhibiting relics that were visually similar to those on display today. There was no proportionate motive for substitution before the twentieth century, since there were neither imminent plans to subject the relics to critical examination nor any available means by which species or organ identity could be verified. Fabricating substitute relics would have required procuring fresh human heart tissue and clotted blood, aging them in a way that precisely replicated the effects of centuries of natural degradation, and tampering with reliquaries without detection.17

Second, the relics were placed under episcopal seals at each canonical inspection. These seals, impressed in wax with the bishop’s unique matrix, could not be removed and replaced without leaving unmistakable traces. Any clandestine attempt at substitution would therefore have been immediately apparent, since it was practically impossible to reverse engineer a matrix or to reconstitute the wax impression once broken. The seals also aged in visible ways—darkening, hardening, and developing cracks—allowing for their continuity to be recognized at a glance. This safeguard was in place throughout the entirety of the modern era. The seals affixed during the episcopal visitation of 1886 remained in place until 1970, when they were broken to allow Dr. Odoardo Linoli to extract fragments for scientific testing.18

Multiple sources confirm that an episcopal inspection took place in 1574. This examination, conducted under Bishop Rodriguez, was later commemorated in a marble epigraph that is visible today in the Church of San Francesco. The inscription, carved in 1636 when the relics were transferred to the Valsecca Chapel, explicitly records the canonical recognition of the relics in 1574. Unlike manuscripts, which can be forged or tampered with, an epigraph is a conspicuous, expensive, and inalterable witness. Its presence demonstrates that, by the late sixteenth century, the relics were already objects of a long-standing devotion, sufficiently established in popular consciousness to warrant episcopal confirmation and epigraphic commemoration.19

The chronicler Fella reports that in 1560 two Basilian monks stole a parchment codex, written in both Greek and Latin, that contained the traditional account of the miracle. The bilingual format is telling: it would have been entirely appropriate for an authentic document written between the 8th and 10th centuries, when Basilian monks migrated to Italy. Meanwhile, it would have been unnecessary and impractical for an early modern forger. Though the codex was stolen, the Franciscans had memorized its contents, and later sources—including the 1636 epigraph—preserve its narrative.20

The earliest surviving literary reference to the relics dates back to the eleventh century. Guitmundo, archbishop of Aversa, recounts the story of a Eucharistic miracle in Italy in which the consecrated bread and wine perceptibly turned into flesh and blood, which were then sealed within the altar by the local bishop for perpetual veneration. Although Guitmund does not name Lanciano, the details correspond to the Lanciano tradition. This reference suggests that the existence of the relics was common knowledge in theological circles in the high Middle Ages.

2.2 - Procurement

The foregoing raises the question of how the Lanciano relics could have come into being at the time that they did. From a skeptical point of view, the only plausible explanation is fraud. That would require a fraudster to obtain human cardiac tissue and blood, fashion them into relics, and successfully introduce them into Lanciano’s devotional life in such a way that they were received as ancient and venerable.

A significant problem for this theory is that it would have made no sense for a fraudster to use a human heart. Acquiring and dissecting a fresh human cadaver would have been unnecessarily difficult and risky.21 Animal flesh was easily accessible, cheap, and indistinguishable from human flesh until the early 20th century. Even if someone insisted on using human flesh, superficial muscle would have sufficed. There were no scientific means available to verify species or organ identity, nor was there a devotional tradition that required Eucharistic relics to be heart tissue.22

But that isn’t the worst of it. Linoli pointed out that “only a very skilled hand in anatomical dissection could have managed—though not without serious difficulty—to obtain from a hollow organ a uniform and continuous ‘slice’ tangential to the surface of the organ, as is inferred from the predominantly longitudinal course of myocardial fibers, taking into account that is precisely in the superficial, mantle-like area of the heart that the bundles of fibers with a longitudinal course… are found.”23

• (Technique) Premodern anatomical dissection was expository rather than analytic, focused on opening organs and separating parts. The skills needed for controlled tangential planing of ventricular walls lay wholly outside the repertoire of Renaissance anatomists. Even if tangential laminar slices had been technically feasible, it is extremely unlikely that a fraudster pioneered and mastered them centuries before anyone else without leaving a trace besides a single artifact.

• (Equipment) A fraudster would have had to maintain sub-degree angular precision and sub-millimeter depth precision throughout the entire dissection. That is not achievable with freehand dissection, especially with premodern instruments. Without mechanical constraints, blade orientation is governed solely by the operator’s joints. Small perturbations are geometrically amplified at shallow angles, making drift that exceeds tolerances inevitable.

• (Fixation) The chemical fixatives required for precision sectioning of soft tissue were not invented until the 19th century, and without them excising a uniform, continuous, transverse section with a tangential cut would have been practically impossible. Ventricles deform under minimal pressure: they shift, collapse, twist, and recoil. Deformations occur within tissue itself, not at the operator-blade interface, so neither skill nor ingenuity could have avoided them.

3. Preservation

3.1 - Preparation

Throughout the medieval and early modern periods, the repertoire of preservation techniques was limited: salt and natron curing, smoke-drying, heat, vinegar or alcohol immersion, and embalming resins or balsams.24 Each leaves behind enduring traces. Salt and natron curing produce crystalline residues and ionically enriched tissue. Smoke-drying and heat discolor tissue, denature proteins, and disfigure microstructure. Immersion in alcohol or vinegar obliterates immunoreactivity. Resins and balsams leave a glossy, resinous surface and distinctive organic residues.25

Linoli determined that none of those methods had ever been applied to the Lanciano relics. His chemical assays showed depressed sodium and chloride levels, the opposite of what would be expected if salt or natron had been applied. Microscopy revealed features that heat or smoke would have obliterated. Immunological testing produced vigorous precipitin reactions, clear AB typing, and fresh-like serum protein fractions, results that cannot be reconciled with the protein denaturation and antigen loss caused by immersion in alcohol, vinegar, or resinous balsams. Nor was there any sign of resinous film, darkened smoke staining, or crystalline deposits on the surface.26

The absence of preservatives and fixitives is decisive evidence against a medieval or early modern fraud. It was common knowledge that flesh and blood needed to be treated. Left to their own devices, they quickly spoil, emit a foul odor, and lose all recognizable form. A fraudster would not have tolerated the risk of immediate putrefaction. Nor would it have cost them anything in terms of credibility to apply a standard technique, since that could have easily been passed off as a custodial decision. The rational course for anyone fabricating relics using perishable materials would have been to employ a familiar, quick, and reliable preservation technique.

3.2 - Storage

Relatedly, without the benefit of artificial stabilization, the relics should have decomposed. Flesh and blood start to decay as soon as they are removed from the body. Coagulated blood clots are among the least stable biological materials: within twenty-four to forty-eight hours they undergo hemolysis and bacterial liquefaction, disintegrating into foul-smelling fluid. Natural desiccation is too sluggish to intervene—surfaces may crust quickly, but interiors remain wet long enough for decay to run its course. From a taphonomic standpoint, the survival of the relics is inexplicable.27

Biological remains are known to perdure only when they are protected by unusually stable environments: constant aridity, deep freezing, or waterlogging. Egyptian mummies, for instance, tend to be well-preserved because they were embalmed and then sealed away from air and humidity.28 By contrast, in addition to being untreated, the Lanciano relics were continuously exposed in liturgical vessels that were neither airtight nor sterile. Linoli noticed mold on the surface of the cardiac tissue—direct evidence of ongoing environmental interaction. The blood clots were stored in a chalice that offered no protection against local environmental fluctuations.29

Furthermore, the biomolecular preservation of the relics would be extraordinary under any storage conditions, up to and including refrigeration in a laboratory.30

• (Abundances) Traces of albumin can be recovered from ancient remains with modern techniques that are sensitive enough to detect nanogram-level quantities of proteins. Globulins, especially α- and β- globulins, almost never register at all.31 Against that background, Linoli’s results are dumbfounding. The electrophoresis protocol that he employed would not have produced sharp, well-defined peaks unless microgram-level quantities of each type of protein were available. That implies that the Lanciano relics have retained serum proteins in abundances that are orders of magnitude greater than comparable remains.32

• (Proportions) Electrophoretic tracings follow a predictable trajectory as blood stains age. Albumin migrates, the α- and β- bands vanish, and the γ- band grows disproportionately large. This ‘gamma inflation’ is so consistent that forensic scientists have suggested using it as a dating technique.33 Not only did the Lanciano relics preserve astonishingly high concentrations of serum proteins, they preserved them in the same relative proportions as fresh serum. Linoli’s electropherogram was consistent with serum taken from a living patient.34 That would have been highly unusual for a blood stain that was less than a year old.

• (Selectivity) Teichmann and Takayama tests, which probe for intact heme, both came back negative. Thin-layer chromatography indicated that hemoglobin breakdown products were present.35 Teichmann and Takayama should have been the last assays to fail: porphyrin rings are chemically resilient, and Teichmann crystals can sometimes be obtained from stains that are decades old, long after labile molecules have disappeared.36 That leaves skeptics with a paradox: the degradation pathway that destroyed heme should have destroyed more labile proteins, yet serum proteins were inexplicably well-preserved.

4. Implications

In view of the foregoing, the best explanation for the origination and preservation of the Lanciano relics is the traditional account: at some point in the first millennium, the consecrated elements perceptibly transformed into flesh and blood during Mass, and they have been miraculously conserved ever since. Moreover, it is apparent that the Eucharistic Miracle of Lanciano was performed with a vindicatory intent that went far beyond the immediate context of the event.

• (Anatomical fine-tuning) The ‘flesh’ is a cross section of the heart that resembles “the image a cardiologist visualizes on an ultrasound screen: it is a parasternal short-axis view, obtained as if ideally ‘cutting’ the heart along a frontal axis.”37 The choice of section indicates that the author of the miracle was concerned with modern verification. It allowed modern science to confirm that the flesh was heart tissue, while also providing modern investigators with evidence against premodern fraud, compensating for the limitations of the documentary evidence. Conversely, it made the relic less intelligible and interesting for premoderns.

• (Taphonomic fine-tuning) The miraculous conservation of the relics indicates that the author of the miracle intends for them to be trans-historical witnesses that evince the authenticity of the Lanciano tradition. In fact, their state of preservation suggests that the author of the miracle has been more concerned with preserving their evidential value for modern scientists than with preserving their visual appearance. On the one hand, the heart tissue is ligneous and mold-spotted, the blood clots are brittle and fissured, and their surfaces are dull and irregular. On the other hand, they have inexplicably retained enough structural integrity and immunoreactivity to confirm organ and species identity.

4.1 - Message

What message did the author of the Eucharistic Miracle of Lanciano intend to convey? At a minimum, it is obvious that the author of the miracle intended to confirm the real presence of Christ in the Eucharist. That presupposes mere Christianity, so it follows that the miracle was intended to be a vindication of Christianity in general.

What about Catholicism in particular? First, it is worth noting that only the Catholic Church teaches transubstantiation: that the substance of bread and wine is wholly changed into the Body and Blood of Christ. Lanciano depicted exactly that: the elements perceptibly became flesh and blood, not merely figuratively nor alongside the bread and wine, but substantially and entirely. Transubstantiation is compatible with Orthodoxy, but it has less resonance with Orthodox theology, which emphasizes the ineffable mystery of the Eucharist. More significantly, the doctrine of transubstantiation has been repudiated by every form of confessional Protestantism.

Second, the distribution of scientifically verified Eucharistic miracles uniquely privileges Catholicism. I intend to survey the evidence for the rest of them in subsequent installments of this series, but for the time being you’ll just have to take my word for it. In addition to Lanciano, several other Eucharistic miracles have been corroborated by laboratory analyses, and all of them occurred in Catholic contexts.38 If Catholicism is true, that makes perfect sense. According to Catholic doctrine, the Eucharist can only be licitly confected by a priest that is in communion with Rome. Meanwhile, if Catholicism is false, the distribution of Eucharistic miracles is baffling.

Might the aforementioned distribution be an artifact of a selection effect? That neglects the vindicatory intent of the miracles. If God intends to use these miracles to send a message, then verification is providential. There would be no reason for him to allow his intended message to be distorted by sampling bias. To avoid giving the misleading impression that Catholicism is uniquely favored, it would be trivial for Him to arrange for the scientific verification of a Eucharistic miracle in a rival sect.

5. Objections

5.1 - Falsification by Linoli?

Objection: During the scientific investigation of the relics in 1970, Linoli was unsupervised. It is entirely possible that he falsified his results.

Reply: First, Linoli never had unfettered control over the relics themselves. He was entrusted only with small fragments for testing; the relics remained in ecclesiastical custody. That meant that he had to be cognizant of the possibility that the custodians would ask an independent researcher to attempt to replicate his findings if any doubts arose. In fact, that safeguard was not merely a theoretical possibility. Recall that an investigator from the University of Siena independently reproduced the results of the absorption–elution test that Linoli performed on the blood clots.

Second, if Linoli falsified his results, he did everything in his power to increase the likelihood that his fraud would be exposed. He voluntarily solicited the opinion of an independent expert, and he voluntarily submitted both photographs and raw data to a scholarly journal. Both of those measures were his idea, they weren’t foisted upon him by anyone else. That is the opposite of the behavior you would expect from a fraudster: instead of minimizing outside scrutiny and retaining plausible deniability, he was much more transparent than he was expected to be. That would have massively and needlessly increased both the risk and complexity of any fraudulent scheme.

Third, Linoli did not have a proportionate motive. Professionally, there was little to gain and much to lose. A physician and professor who associated himself with a miraculous claim risked being regarded with suspicion by colleagues, collaborators, and journal editors. Had his study been discredited, the reputational damage would have been catastrophic. As a highly educated Catholic, Linoli understood that bearing false witness—especially about a Eucharistic miracle—would endanger his soul. Historically, the fabrication of relics has usually been motivated by avarice. For a properly catechized Catholic, a pious fraud is a contradiction in terms.

Fourth, it would not have been practically feasible for Linoli to fabricate the micrographs that he published in his scholarly journal article. In the 1970s, photomicrography was film-based and digital editing was decades away. Falsifying the micrographs would have required Linoli to get his hands on untreated, ancient cardiac tissue. Yet such material is, for all intents and purposes, unobtainable. Pathology collections preserve organs in formalin; archaeological remains rarely retain recognizable myocardium, and when they do, it is mineralized or mummified. It simply would not have been possible for a provincial physician to acquire the centuries-old, naturally desiccated cardiac tissue depicted in Linoli’s micrographs.

Fifth, even if Linoli falsified his results in their entirety, that would only partially explain the origination and preservation of the relics. To fully explain the data, the skeptic has to posit that Linoli’s fraud was a cover-up for a similarly elaborate and nonsensical premodern fraud. Many of the features that exclude a premodern fraud can be inferred from the macroscopic appearance of the relics alone. Although the data that establishes species identity, absence of preservatives, and biomolecular preservation would be undercut, the historically implausible dissection and exceptional preservation in unfavorable storage conditions would be left as remainder.

14

Linoli, O. (1971).

Serafini, F. (2025). Praising a glorious page of forensic pathology: a reply to Kelly Kearse. Forensic Science, Medicine and Pathology.

Serafini, F. (2025). AB in Lanciano, bacterial contamination? Let’s ask Linoli! A Cardiologist Examines Jesus (Substack).

Franco Serafini

AB in Lanciano, bacterial contamination? Let's ask Linoli!

In 2022, thanks to the friendship and trust of the Guardian of the Shrine, Father Fabrizio De Lellis at the time, I had the opportunity to spend a few hours in the archives of St. Francis in Lanciano. It was a great thrill and privilege for me to read the correspondence, spanning decades, between Prof. Odoardo Linoli and the friars who succeeded one ano…

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5 months ago · Franco Serafini