Damien Marsic, PhD and Mehran Sam, PhD
Association of Raelian scientists
P.O. Box 570935
Las Vegas NV 89157-0935

Corresponding author: Mehran Sam, scientist@rael.org


Religious institutions such as the Catholic Church exert enormous influence on the life of large numbers of individuals, despite professing fantastical claims that are seldom questioned or challenged. In this study we tested the Catholic dogma of transubstantiation by DNA analysis. Results showed unequivocally that the rituals performed by the priests during the Eucharist sacrament have no detectable effect on the substance of altar bread at the DNA level. We wish to encourage others to engage in similar studies and help religious organizations rid themselves of superstition and irrational beliefs, thus contributing to elevate fellow human beings.


With 1.2 billion members worldwide, the Roman Catholic Church exerts its influence on a significant portion of the world population. One of the important doctrines of Catholicism affirms that the wheat wafer (also called hostia, host or sacramental bread) used in the sacrament of Eucharist or Holy Communion becomes in actual reality the body of Jesus Christ, in a process called transubstantiation. The doctrine of transubstantiation was officially defined during the council of Trent in 1551 CE and holds that the consecration that takes place during Eucharist literally changes the substance of the bread into the substance of the body of Christ. Understandably, the claim has been viewed with skepticism among non-Catholics, but also among increasing numbers of Catholics who are being disillusioned with the Church's disconnect with today's scientific understanding and its insistence on upholding irrational dogmas. We propose to test the credibility of the transubstantiation dogma by analyzing the substance of consecrated sacramental bread. Host samples collected in Catholic churches during communion were tested for the presence of wheat and human DNA using PCR, and compared to human and wheat controls.



Consecrated hosts were collected during communion in 5 different Catholic churches in the United States and Canada and immediately placed into clean plastic bags to avoid contamination. A sample of cultured HEK-293 cells was used as the human control. Unconsecrated altar bread purchased from a church supply store was used as the wheat control.

DNA isolation

Human DNA was extracted from the control human cells using the GeneJet genomic DNA purification kit (Thermo Scientific, USA) according to the manufacturer's instructions.

Isolation of DNA from the altar bread samples (both consecrated and unconsecrated) was performed as follows. Bread fragments were placed into 2 ml microcentrifuge tubes into which 1.3 ml of DNA extraction solution (150 mM NaCl, 0.05 N NaOH, 2.5 mM EDTA, 0.25% SDS) was added. Tubes were then incubated at 65°C while being shaken at 900 RPM for 20 minutes. The tubes were then centrifuged at 21000 g for 5 minutes and 200 µl of supernatant was transferred to fresh tubes. DNA was purified from the supernatant samples using DNA Clean & Concentrator kit (Zymo Research, USA) according to the manufacturer's instructions.

DNA amplification

The amplification primers used in PCR are listed in Table 1. All samples and controls were amplified using both pairs of primers in separate reactions. PCR mixtures included 0.2 mM each dNTP, 0.2 µM each forward and reverse primer, 1/20 volume template, 25 mU/µl OneTaq DNA polymerase (New England Biolabs, USA) and 1x OneTaq buffer. Cycling parameters were: 30 s initial denaturation at 94°C; 33 cycles of 20 s denaturation at 94°C, 30 s annealing at 52°C and 45 s extension at 68°C; 5 min final extension at 68°C. Amplification products were visualized on a 1.5% agarose electrophoresis gel alongside a 50 bp DNA ladder.


Primer pairs that would allow to amplify specifically human and wheat DNA respectively under the same PCR conditions (same annealing temperature and product size range) were searched for in the available literature. Primers F7901 and R8311 [1], which target region 7901 to 8311 of the human mitochondrial genome, and Dgas44-F and Dgas44-R [2], which target the D genome-specific repetitive DNA sequence Dgas44 in wheat, were selected as human-specific and wheat-specific amplification primers respectively (Table 1).

An electrophoresis gel showing DNA amplification products is shown in Fig. 1. Negative controls (water as template, lanes NC) show no amplification product, indicating that PCR reagents were free from human or wheat DNA contamination. Human controls (lanes HC) show the expected 411 bp amplification product with human primers and no amplification with wheat primers, confirming that human DNA can be detected using the selected human primers. Wheat controls (lanes WC) show amplification products with both pairs of primers, with a more intense band with wheat primers. The human DNA detected in the wheat control was likely introduced during handling of the bread sample. The 5 consecrated bread samples (lanes 1 to 5) analyzed using wheat primers show the 286 bp band that would be expected for regular bread material but that should be absent if wheat DNA had somehow been changed into human DNA through the consecration performed by priests. Only one sample (number 5) shows a 411 bp PCR product when amplified using human primers, with a much lower band intensity than the 286 bp product obtained with wheat primers. All other consecrated bread samples show no amplification using human primers. Sample 5 is likely a case of human contamination during handling, as inferred by comparison with the wheat control. Taken together, these results are consistent with the consecrated sacramental bread samples being regular bread samples, and inconsistent with the claim of transubstantiation or the idea that the consecration during the Eucharist sacrament would change the wheat DNA into human DNA.


Using science to test a religious claim

It could be argued whether supernatural claims can or should be tested by science. The famous view advocated by Stephen Jay Gould that science and religion are “non-overlapping magisteria” [3] has been extensively criticized by both scientists such as Richard Dawkins [4] or Yonathan Fishman [5] and philosophers like Russell Blackford [6]. The transubstantiation claim by the Catholic Church is particularly relevant because of the doctrine's insistence that the transformation of bread into the body of Christ is not symbolic but a physical reality. The claim is both fantastical and easy to test. However, the main reason for this study was to answer requests by former Catholics recovering from dogmatic indoctrination in the hope that it would help others develop informed opinions on the validity of religious dogmas.

Rationale for testing DNA

As believers themselves agree that the appearance, taste and texture of sacramental bread are retained after consecration, it is unclear what the “substance” that is allegedly transformed could be. If the host still looks like bread and tastes like bread after having been consecrated, the molecules responsible for the taste and texture can not have been affected. This leaves DNA as the most probable candidate. Indeed, if wheat DNA in a piece of bread could be replaced by human DNA, the change would not affect the bread's texture or taste. On the other hand, it could be argued that DNA represents the actual “substance” of any biological material because it contains the information that defines that material and could be used to create a copy of it. Therefore, testing the transubstantiation claim by DNA analysis seems a quite reasonable approach to take. To critics who would question the assumption that the body of Jesus Christ has human DNA, it can easily be replied that all Christians believe that Jesus had a biological mother (Mary) who was a human being. Uncontroversially, Mary gave her son half of her genome as well as her mitochondrial DNA, no matter who the father was. If Mary or any of her children was tested using the human-specific PCR primers used in this study, the test would be positive, especially because it specifically detects mitochondrial DNA, which is transmitted exclusively by the mother.

Ethical concerns

This study could be criticized on ethical grounds for using deception to collect samples. Indeed, the individuals who provided us with the consecrated hosts obtained them during communion, pretending to be believers, and transferred them discretely into plastic bags instead of ingesting them. However, these individuals were all former Catholics who had felt victimized by the Church's dogmatic teachings and saw this action as contributing to their recovery. The moral dilemma of obtaining samples through deception is to be contrasted with the ethics of enrolling non-consenting newborns into a religious organization, endoctrinating children with unquestionable dogmas and instilling fear, guilt and shame in them with long-lasting consequences for their psychological well-being. Anyway, in agreement with our results, we are confident that no sentient being was physically harmed in the course of this study.


This study falsifies the claim that a religious ritual performed by a priest can actually change the substance of a bread wafer into the substance of a human body. It is by no means an attack on religion, but rather a small step in the refutation of superstition and irrational beliefs, an important role of science, at least since the age of Enlightenment. Religions can have important social benefits, and even more so when they evolve with scientific knowledge and update their claims and beliefs accordingly. We hope that this study will encourage others to use the tools of science to test other religious claims, thus contributing to bring enlightenment to their fellow human beings who still live under the influence of dogmatic religious doctrines.


1. Levin, B. C., Cheng, H. & Reeder, D. J. A human mitochondrial DNA standard reference material for quality control in forensic identification, medical diagnosis, and mutation detection. Genomics 55, 135–146 (1999).
2. Bryan, G. J., Dixon, A., Gale, M. D. & Wiseman, G. A PCR-based Method for the Detection of Hexaploid Bread Wheat Adulteration of Durum Wheat and Pasta. J. Cereal Sci. 28, 135–145 (1998).
3. Gould, S. J. Rocks of ages: science and religion in the fullness of life. (Ballantine Pub. Group, 1999).
4. Dawkins, R. The God delusion. (Houghton Mifflin Co, 2006).
5. Fishman, Y. I. Can Science Test Supernatural Worldviews? Sci. Educ. 18, 813–837 (2009).
6. Blackford, R. Stephen Jay Gould on Science and Religion. Quadrant 365, 8–14 (2000).


Table 1: Human-specific and wheat-specific amplification primers

Table 1

Fig. 1: Agarose gel electrophoregram of PCR amplification products.

M: 50 bp DNA ladder; NC: negative control; HC: human control; WC: wheat control; 1 to 5: consecrated scramental bread samples. Left: reactions using human-specific primers; right: reactions using wheat-specific primers.

Fig 1 Host DNA