DNA analysis

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Structural model of a section from the DNA double helix with 20 base pairs

As DNA analysis , DNA testing , DNA analysis , DNA testing , gene analysis or genetic test are molecular biological refers to methods which the deoxyribonucleic study (German abbreviation DNS, English DNA = deoxyribonucleic acid), in order to draw conclusions about various genetic aspects of the individual to be able to pull.


DNA analyzes are performed for a variety of purposes, v. a. to the following:

  • For criminal purposes: one examines crime scene traces in order to find DNA traces of individual living beings (e.g. from the perpetrator). In this context one often speaks of the “ genetic fingerprint ”.
  • Clarification of questions of relationship such as B. Parentage reports .
  • medical-diagnostic use (for example with human DNA), e.g. B.
    • clarify the genetic basis of an existing disease (medical research),
    • Investigate predispositions to disease. The professional association of German human geneticists e. V. (BVDH) maintains a list of genetically caused diseases that can currently be examined in German-speaking countries in appropriate facilities using DNA analysis. In May 2010, the number of diagnosable diseases was 917, in comparison to this, slightly more than 3,000 monogenetic hereditary diseases have been molecularly characterized worldwide and could theoretically also be investigated using DNA analysis.
    • Blood tests
  • Food controls
    • Detection of genetically modified varieties which are subject to an import ban.
    • Quality assurance of food (example: truffle ).
  • genetics
  • DNA analyzes for individuals by private companies. The two most popular areas of application are:
    • Genetic genealogy or genealogical DNA tests
    • Examination of the genetic material for genetic diseases and other predispositions


DNA molecule 1 differs from DNA molecule 2 in a single base pair.

Methods of studying diseases

Methods of determining identity

Determination of samples of old age

Problem, criticism

Evolution of the cost of genome sequencing since 2001

The validity of genetic tests and the possibility of their meaningful application in health care are disputed by numerous scientists. In addition to an unclean statistical evaluation of the results trimmed to reports of success, the general connection between “disease genes” and the specific symptoms and diagnosed diseases is criticized. In reality, the dependencies postulated by researchers and companies would turn out to be much lower, and many diseases would be significantly more strongly influenced by external influences and lifestyle than by genes. There is similar criticism from providers who specialize in DNA tests for genetic genealogy . It is also frequently criticized that genetic test providers do not sufficiently point out risks to private customers when sending in DNA samples, storing, analyzing and storing them as well as by publishing information. Commercial providers are not and most of the time are not obliged to adhere to the ethical principles of scientific DNA studies. The following risks are listed:

  • Through DNA analysis it is possible to determine hereditary defects or predispositions and the likelihood of diseases arising from them.
  • Depending on the DNA analyzed, these conclusions can also be extended to relatives.
  • An insurer can use the information on assessments to determine a contribution rate, or the person to be insured must personally disclose known analysis results.
  • Available information on DNA markers of a test person can be used in the case of DNA traces at crime scenes to suspect the test person or his relatives as the perpetrator (even if this is not legally permitted everywhere). The determinability of ever smaller DNA traces also leads to errors (see Heilbronn phantom ).

The data protection of the "genetic privacy" has become an issue (status 2014):

  • Once data has been published on the Internet, it is practically impossible to delete it (since it cannot be determined who has already made a copy).
  • The personal DNA information held by the testing company can be stolen, published, or sold.

After a murder in Freiburg in October 2016 , the Baden-Württemberg Justice Minister Guido Wolf (CDU) campaigned to change the code of criminal procedure so that the eye color, skin color and hair color of an unknown tracer can be determined on the basis of DNA samples. The trace commission , the scientific body of forensic medicine and forensic science institutes in Germany, also spoke out in favor of expanding DNA analysis. After lengthy discussions, the amended version of Section 81e (2) of the Code of Criminal Procedure (admissibility of examinations to determine the color of eyes, hair and skin as well as the age of unknown persons) was passed by the Bundestag on November 15, 2019. In Bavaria, such a power was created in May 2018 with a controversial amendment to the Bavarian Police Task Force.

See also

further reading

  • Peter M. Schneider , Barbara Prainsack, Manfred Kayser: Extended forenic DNA analysis to predict appearance and biogeographical origin. In: Deutsches Ärzteblatt. Volume 116, Issue 51–52, December 23, 2019, pp. 873–880.

Broadcast reports

Web links

Commons : DNA test  - collection of pictures, videos and audio files

Individual evidence

  1. Human Genetic Quality Network (HGQN) - A database of the BVDH. Professional Association of German Human Geneticists V., accessed April 29, 2010 .
  2. For " GM rice " (August 2006 by the European Commission ): import ban on US GM rice - emergency procedure stops import of US GM rice. (No longer available online.) Greenpeace market check, August 25, 2006, archived from the original on July 13, 2013 ; Retrieved March 8, 2012 .
  3. DNA analysis online: surfing the genome. In: Süddeutsche Zeitung . January 22, 2008.
  4. Heike Le Ker: “Like a fortune teller”. In: Spiegel Online - Medicine. December 12, 2011, accessed on March 7, 2012 ( interview with medical ethicist Urban Wiesing ).
  5. ^ Application for a free genotyping. openSNP.org - crowdsourcing genome wide association studies , February 20, 2012, accessed March 5, 2012 .
  6. See also: Videos and Slides on the recent talks. openSNP.org (2nd video in German).
  7. Anette Dowideit: Experts warn of new internet genetic tests. In: World Online Medicine. June 4, 2008, accessed March 5, 2012 .
  8. ^ "Genetic tests for the insurance industry" - Statement by the Parliamentary State Secretary in the Federal Ministry of Health Gudrun Schaich-Walch on the subject of "Genetic tests for the insurance industry". (PDF; 19 kB) (No longer available online.) May 3, 2002, archived from the original on March 5, 2016 ; Retrieved March 7, 2012 .
  9. Alexander Dix : DNA analysis in criminal proceedings. (No longer available online.) State Commissioner for Data Protection and for the Right to Access Files Brandenburg, March 5, 2005, archived from the original on August 4, 2012 ; Retrieved March 7, 2012 .
  10. New regulation of DNA analysis for the purposes of criminal proceedings. Federal Court of Justice , accessed on February 12, 2017 .
  11. DNA links 1991 killing to Colonial-era family. In: CNN . October 1, 2012, accessed May 30, 2012 (Y-DNA of a sex offender is searched using public DNA genealogical databases).
  12. Marc Herb: Ethical aspects of DNA analysis in law enforcement. (PDF; 0.2 MB) (No longer available online.) University of Applied Sciences Stuttgart - University of the Media , January 2004, archived from the original on June 19, 2006 ; Retrieved March 7, 2012 .
  13. Lea Wolz: The DNA analysis is safe. In: Stern.de - Health. March 26, 2009, accessed March 7, 2012 .
  14. Michael Stang : Chopped Genes. In: Deutschlandfunk - science in focus . 3rd October 2014.
  15. DNA analyzes are to be expanded. In: FAZ.net. December 14, 2016.
  16. Press release: Bundestag decides to modernize the criminal procedure accessed on December 25, 2019
  17. ^ Zeit-online: Bavaria announces changes to the controversial police law , accessed on August 24, 2020
  18. Netzpolitik.org: Search for the genetic phantom: Bavaria wants to allow controversial DNA analysis, accessed on August 24, 2020