Proc. R. Soc. B doi:10.1098/rspb.2009.2019 (2010)

Credit: R. SOC.

Improved techniques have yielded well-preserved DNA from fossilized eggshells, highlighting a potential new source of ancient genetic material.

Eggshells are commonly found at fossil sites, but previous attempts to pull DNA from them have failed. Michael Bunce at Murdoch University in Perth, Western Australia, and his colleagues took several measures to optimize DNA extraction, including warming a DNA-isolation solution containing powdered eggshell to 95 °C.

The authors tackled the eggs of several extinct species, including the New Zealand giant moa (Dinornis robustus; microscope image of eggshell's inner surface pictured). They say that their procedure released the DNA (red arrows) from the eggshell's calcium carbonate crystalline matrix, allowing them to double their yield. They also found that eggshells are less contaminated with bacterial DNA than fossil bones.