# Comparing the Quality and Quantity of Extracted Deoxyribonucleic Acid (DNA) From Formalin-Fixed and Embalmed Tissues at Monthly Intervals Over Six Months

## TL;DR

This study compares DNA quality and quantity from embalmed and formalin-fixed tissues over six months to determine the best tissue for genomic studies.

## Contribution

Identifies skin tissue as the best candidate for genomic studies due to its higher purity in embalmed cadavers.

## Key findings

- Formalin-fixed tissues showed higher DNA concentration than embalmed muscle, but the difference was not statistically significant.
- Skin tissue preserved in embalming fluid had the highest DNA purity, making it the best candidate for genomic studies.
- Liver, kidney, and muscle tissues required purification before downstream procedures due to lower purity.

## Abstract

Background: Cadavers are the principal materials used for teaching and learning human anatomy. The dead bodies received from the Department of Anatomy are chemically treated (embalmed) to be learner-ready, arrest further decomposition, and preserve the body in a life-like state. The present study was designed to analyze this knowledge gap by extracting deoxyribonucleic acid (DNA) from different tissues of cadavers and to determine which tissue is more likely to provide DNA of suitable quality and quantity.

Materials and methods: This observational study was conducted at the Department of Anatomy, Maulana Azad Medical College (MAMC), New Delhi, India. It lasted one year, from January 2021 to January 2022. The Institutional Ethics Committee (IEC), MAMC, New Delhi, India, granted ethical approval under letter number F1/IEC/MAMC/82/10/2020/No.29 dated January 14, 2021.

Results: The mean concentration of all four tissues in all six bodies over six months was higher for formalin-fixed than embalmed muscle, but it was statistically not significant. It has been observed that the mean concentration of all tissues at 260/280 and 260/230 optical density was found to be statistically significant at a p value of less than 0.001. The preservatives used were formalin and embalming solution. While comparing data from all bodies, only muscles at 260/280 showed statistically significant results with a p value of 0.03.

Conclusion: The study concluded that for genomic studies, from the tissue preserved in embalming fluid among the four tissues studied, including liver, kidney, skin, and muscle, skin tissue is the best candidate, as purity is an essential requirement. The extracted DNA from the liver, kidney, and muscle tissues will require purification before being subjected to downstream procedures.