The linguistic root of tzaraath may mean smiting, in comparison with Arabic, in reference to a Talmudical explanation that it serves as a punishment for sin; it is quite possible that tzaraath was a general term for certain types of skin disease, rather than a particular condition, and the Talmud maintains a similar view, arguing that tzaraath referred generally to any disease that produces sores and eruptions on the skin.
Investigations of keratins extracted from wool by reduction hydrolysis and by alkaline hydrolysis showed that their chemical compositions and secondary structures were similar to original wool. The keratin isolates were similar in amino acid, Amides I and II, and secondary structure to each other and to original wool.
If keratin is to be useful in a hair care product, then it is preferable that it comes from wool from sheep farmed in New Zealand. Wool keratins and hair keratins are much closer in form and function than other keratins in other species.