 |
||||
| Home What is aDNA? Sample Requirements Database About aDNA.info Current Research Contact Information Links aDNA News Archive |
Sample RequirementsCells containing DNA are found in all biological tissues and secretions. Examples include bones, teeth, hair, seeds, skin, saliva, sweat, plant fibers, bacteria, fungi, blood, urine, and feces. The volume of sample needed depends on the type and condition of the specimen. The primary challenge in recovering ancient DNA is that over time, and when exposed to suboptimal environmental conditions, DNA strands are subject to degradation, reducing the original long strands into short, broken fragments. Degraded DNA is easily contaminated by modern DNA from the burial environment or from researchers who handle the ancient DNA specimen. Contaminant DNA makes isolation of the ancient DNA far more difficult. For this reason, it is imperative that specimens to be sent in for aDNA analysis be stored and handled using a sterile technique. Ancient DNA analyses are conducted in what are known as "clean" laboratories. These are areas designed specifically to prevent contamination by modern DNA. Special air filters and positive air flow are used so that airborne particles from outside the laboratory cannot enter. Scientists wear special garments to prevent their own skin cells from being shed into the laboratory. Different steps of the extraction and analysis process take place in physically separated areas. |
|||
 |
||||