**4. Conclusion**

Based on our data, when analyzing highly degraded DNA, it is preferable to use information from all types of DNA markers such as autosomal STRs, X- and Y-STRs and mitochondrial hypervariable region sequence to get the best possibleindividual DNA profile, especially in difficult cases.

In the near future, in order to obtain the fullest possible individual DNA profile, it will be useful to include information about phenotyping features (such as skin, hair or eye color, skeletal particularities etc.) and biological age based on microarray analysis, next-generation sequencing SNP data, state of methylation and specific gene expression analysis.

But the highest percentage of reliable and reproducible DNA profiles can be obtained from the odontoid process of the 2nd cervical vertebra, long tubular bones of the lower (femoral) and upper (shoulder) limbs, as well as from teeth. In addition, even single hairs and burnt tissues can constitute a source for successful DNA identification.

The results of our analysis made it possible to formulate a number of recommendations regarding the collection of human remains from the crime scene in order to enable successful DNA analysis.

If a complete skeleton or unidentified corpse is found:


**71**

**Author details**

Elena V. Ioganson1

and Olga A. Kravtsova2

**Acknowledgements**

**Conflict of interest**

, Marat I. Timerzianov1

1 Republic Bureau of Forensic Medicine, Kazan, Russia

\*Address all correspondence to: okravz@yandex.ru

\*

The authors declare no conflict of interest.

2 Kazan Federal University, Kazan, Russia

provided the original work is properly cited.

, Marina V. Perelman1

*Reliability and Reproducibility of DNA Profiling from Degraded Samples in Forensic Genetics*

When working at the crime scene special attention should be paid to searching and removal of small bones and fragments to make it possible to obtain complete genetic profiles. However, it is necessary to understand that not all objects allow the preservation of DNA for a long time [13] and bone remains are one of the most controversial objects. On the one hand, the physiological structure of the bone allows DNA preservation for a long time, but on the other hand, it is very difficult

Besides, in the process of DNA extraction, a sample can be severely damaged or even destroyed, and as a result a false-positive result can be obtained (such as by contamination by other DNA samples) or a false-negative result (such as by the presence of inhibitors). That is why it is very important to eliminate the errors due

Moreover, probability estimation in identification analysis also plays an important role in DNA analysis interpretation. Based on our experience, the Bayesian probability gives the most reliable conclusion about the non-random coincidence of determining genetic profile in case of positive individual identification [14]. In addition, it should be taken into account that for working with degraded DNA samples qualifications and experience of a geneticist should be confirmed with

Finally, it is important that the results of DNA identification should not be the only prosecution evidence. Where there are discrepancies with the materials of the investigation, it is necessary for further expert studies to be undertaken which take into account all the circumstances of the crime that has been committed [15, 16].

We would like to thank forensic doctors Pankratova Irina V., Shuvalova Inga I.,

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

Spulnik Sergey V. for providing information about cases of bones analysis.

*DOI: http://dx.doi.org/10.5772/intechopen.98300*

to extract DNA from some types of bones.

to the reproducibility in DNA analysis.

special competence documents.

*Reliability and Reproducibility of DNA Profiling from Degraded Samples in Forensic Genetics DOI: http://dx.doi.org/10.5772/intechopen.98300*

When working at the crime scene special attention should be paid to searching and removal of small bones and fragments to make it possible to obtain complete genetic profiles. However, it is necessary to understand that not all objects allow the preservation of DNA for a long time [13] and bone remains are one of the most controversial objects. On the one hand, the physiological structure of the bone allows DNA preservation for a long time, but on the other hand, it is very difficult to extract DNA from some types of bones.

Besides, in the process of DNA extraction, a sample can be severely damaged or even destroyed, and as a result a false-positive result can be obtained (such as by contamination by other DNA samples) or a false-negative result (such as by the presence of inhibitors). That is why it is very important to eliminate the errors due to the reproducibility in DNA analysis.

Moreover, probability estimation in identification analysis also plays an important role in DNA analysis interpretation. Based on our experience, the Bayesian probability gives the most reliable conclusion about the non-random coincidence of determining genetic profile in case of positive individual identification [14]. In addition, it should be taken into account that for working with degraded DNA samples qualifications and experience of a geneticist should be confirmed with special competence documents.

Finally, it is important that the results of DNA identification should not be the only prosecution evidence. Where there are discrepancies with the materials of the investigation, it is necessary for further expert studies to be undertaken which take into account all the circumstances of the crime that has been committed [15, 16].

### **Acknowledgements**

*Forensic Analysis - Scientific and Medical Techniques and Evidence under the Microscope*

burnt finger phalange (**Figure 17**) and the victim's clothes.

(**Figures 18** and **19**).

**4. Conclusion**

ness of the crime committed.

gene expression analysis.

DNA identification.

or a tooth;

enable successful DNA analysis.

If a complete skeleton or unidentified corpse is found:

and upper limbs as well as 2nd cervical vertebrae;

(liver, blood vessels, etc.) for DNA identification.

DNA profile, especially in difficult cases.

obtained in the material of the lower extremities, burnt liver fragments (**Figure 16**),

Thus, the testing that was conducted made it possible not only to identify the deceased man but also to prove the circumstances of the crime committed. This assisted the process of gauging the circumstances of the offending and the serious-

Based on our data, when analyzing highly degraded DNA, it is preferable to use information from all types of DNA markers such as autosomal STRs, X- and Y-STRs and mitochondrial hypervariable region sequence to get the best possibleindividual

In the near future, in order to obtain the fullest possible individual DNA profile, it will be useful to include information about phenotyping features (such as skin, hair or eye color, skeletal particularities etc.) and biological age based on microarray analysis, next-generation sequencing SNP data, state of methylation and specific

But the highest percentage of reliable and reproducible DNA profiles can be obtained from the odontoid process of the 2nd cervical vertebra, long tubular bones of the lower (femoral) and upper (shoulder) limbs, as well as from teeth. In addition, even single hairs and burnt tissues can constitute a source for successful

The results of our analysis made it possible to formulate a number of recommendations regarding the collection of human remains from the crime scene in order to

• in the absence of deeply penetrated putrefactive changes, it is advisable to provide bones with remnants of soft tissues, not only their single fragments;

• it makes sense to provide, first of all, ribs and long tubular bones of the lower

• it is advisable to provide several bones from one body, such as a rib, long bone,

• if an incomplete skeleton or individual bones are found, it is advisable to provide all the discovered bone remains, so that the forensic geneticist can

• if a body is found after a fire, it is good practice to provide tissue fragments

independently decide which of the bones to examine first;

According to the preliminary investigation, the victim had a sister so in order to complete human identification, mtDNA analysis was carried out. Hypervariable regions, HVS-1 and HVS-2, of mtDNA D-loop sequencing was performed by the MitoPlex system (Gordiz, Russia). Individual sequences were also determined in the DNA samples extracted from lower limbs, burnt liver fragments and clothing items of the missing man, as well as from the buccal swabs of the woman believed to be the sister of the deceased man

**70**

We would like to thank forensic doctors Pankratova Irina V., Shuvalova Inga I., Spulnik Sergey V. for providing information about cases of bones analysis.

### **Conflict of interest**

The authors declare no conflict of interest.

### **Author details**

Elena V. Ioganson1 , Marat I. Timerzianov1 , Marina V. Perelman1 and Olga A. Kravtsova2 \*

1 Republic Bureau of Forensic Medicine, Kazan, Russia

2 Kazan Federal University, Kazan, Russia

\*Address all correspondence to: okravz@yandex.ru

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
