Methods of extraction of genetic material from hard tissues: A review of the 21st century advancements

Abstract

Skeletal remains are the only source of the genetic material of decomposed organisms or once-lived species. Unlike, soft tissues they are highly mineralized, and their anatomical and morphological structure prevents their deformation in the presence of adverse environmental factors. Therefore, bones and teeth protect the Deoxyribonucleic Acid (DNA) inside them. Obtaining DNA from hard tissues comes with challenges like contamination, degradation, PCR inhibitors, damage done by the environment on remains, etc. Traditional methods have been in use for a long time. To overcome the challenges in extracting DNA from hard tissues, researchers introduced various modifications, with time, to the standard procedures. We have reviewed the innovative approaches developed during the period ranging from 2000 to 2024, using the Google Scholar search engine. The last innovative method was discovered in 2021. Each method solves a particular challenge and makes it easier for future researchers to opt for a suitable protocol according to the specific requirements of their study. The methods were renamed based on their core specification, such as Carrier-Mediated Precipitation Method, CTAB Method, Buffered-Nondestructive Extraction Method, MDNAMI Method, Demineralization protocol, Rapid Column-based DNA Extraction, Bone Powdering and Bone Slicing, Short Fragmented DNA Extraction, Highly Degraded DNA Extraction, and Non-destructive Tooth DNA Extraction. A collaboration of researchers from forensic science, anthropology, archeology, evolutionary biology, molecular biology, etc. may develop more sophisticated techniques that ease extraction, increase yield, and reduce contamination of DNA from hard tissues.