Schweitzer’s team detected DNA in three independent ways. Indeed, one of these chemical tests and specific antibodies specifically detect DNA in its double–stranded form. This shows that it was quite well preserved, since short strands of DNA less than about 10 bp don’t form stable duplexes. The stain DAPI 19 lodges in a groove of a stable double helix, which requires even more bp.
Again, the first possible response by long-agers is “contamination”. But the DNA was not found everywhere, but only in certain internal regions of the ‘cells’. This pattern was just like in ostrich cells, but nothing like biofilm taken from other sources and exposed to the same DNA-detecting pattern. This is enough to rule out bacteria, because in more complex cells (such as ours and dinos), the DNA is stored in a small part of the cell—the nucleus.
Futhermore, Schweitzer’s team detected a special protein called histone H4. Not only is yet another protein a big problem for millions of years, but this is a specific protein for DNA. (DNA is Deoxy-riboNucleic Acid, so is negatively charged, while histones are alkaline so positively charged, so they attract DNA). In more complex organisms, the histones are tiny spools around which the DNA is wrapped. 20 But histones are not found in bacteria. So, as Schweitzer et al. say, “These data support the presence of non-microbial DNA in these dinosaur cells.” 11
It’s hard to improve on one of Mary Schweitzer’s early quotes:
It was exactly like looking at a slice of modern bone. But of course, I couldn’t believe it. I said to the lab technician: “The bones are, after all, 65 million years old. How could blood cells survive that long?” 21
