What did Franklin originally call the drier form of DNA?

What did Franklin originally call the drier form of DNA? She called it “crystalline.”

Franklin’s DNA experiments revealed that the molecule could adopt different physical forms depending on how much water the fibre absorbed. The drier form produced a relatively ordered, crystal-like X-ray diffraction pattern, so she initially called it the “crystalline” form. It was later designated the A form, or A-DNA.

The contrasting hydrated form was initially called “wet” and later became known as the B form, or B-DNA. Franklin and Gosling could move DNA between these states by changing the relative humidity around the fibre. This was crucial because earlier diffraction photographs often mixed the two forms, making interpretation difficult.

“Crystalline” does not mean Franklin had isolated a conventional three-dimensional DNA crystal. It describes the greater order of the fibre and the character of its diffraction pattern. The A form is shorter and wider than B-DNA and contains less water, while B-DNA is the more familiar biological double-helix form.

Another common confusion is reversing the labels: the dry form is A-DNA and crystalline; the wetter form is B-DNA and paracrystalline or wet.