How Anglo-Saxon are the English people?

Sites from which samples were extracted EDIT: a subsequent study in 2022 by Gretzinger et al has revealed that Anglo-Saxon DNA is actually as much as 48% in the most populated region of England. Read more.

This paper, Schiffels et al (2016), was a revealing study in ancient Anglo-Saxon DNA. It looked at DNA from 10 skeletons from 3 sites in East England: Hinxton, Oakington and Linton dating from before and after the Anglo-Saxon invasions. This study is better at estimating the genetic impact of Anglo-Saxons on England than other studies which only compare modern British people to modern populations on the continent.
"we estimate that on average the contemporary East English population derives 38% of its ancestry from Anglo-Saxon migrations."

"The middle Anglo-Saxon samples from Hinxton (HS1, HS2 and HS3) share relatively more rare variants with modern Dutch than the Iron Age samples from Hinxton (HI1 and HI2) and Linton (L). The early Anglo-Saxon samples from Oakington are more diverse with O1 and O2 being closer to the middle Anglo-Saxon samples, O4 exhibiting the same pattern as the Iron Age samples, and O3 showing an intermediate level of allele sharing, suggesting mixed ancestry."
In other words, Anglo-Saxons mixed with the Celtic Britons very quickly but there were also subsequent arrivals of more Germanic people from the continent. Geneticists using the term Anglo-Saxon in relation to the 38% figure are specifically referring to the newcomers. But when historians refer to the Anglo-Saxons, they don't just mean the Germanic people who arrived in the Migration era, they are referring to a full 600 years of English history!
If you were to ask the question of how much DNA we have from an average Anglo-Saxon, ranging from the mixed woman labelled O3, who lived in the early AS era around 500 AD, to any Anglo-Saxons living in the 7th, 8th or 9th century, then the % would be MUCH higher than 38%! The fact is that the DNA of Anglo-Saxon England from was for most of the AS period the same as that of modern ethnically English people ie: a mix of continental Germanic and Iron Age British Celtic.