I didn't think that they had scriptural backing for the use of blood parts but I haven't been in over a year so maybe they have added some. Though, I found out something that I thought was rather interesting. I know a couple that are Orthordox Jews, almost Hasidic (sp?), they have rules on everything. Their meat has to be soaked in a brine solution, no eating of blood is allowed at all. They can't use a knife that has ever cut meat to cut anything else except meat but when I asked them what their stand was on blood transfusions, they told me that blood transfusions are life saving and that life is more important than the law.
Anyway, just a side point. Sorry I am not more help with the scriptural aspect.
Loruhamah