calculating the amount of DNA in the final concentration - DNA extracted from bone powder (May/21/2007 )

I've extracted DNA from 0.521g of bone powder and after purification, extraction and rehydration in 50 micro litre of EB buffer, I've used 4 micro litre of my DNA sample in my pcr. However, I need to figure out how to calculate my final DNA concentration to compare with another sample, would anyone know how i should go about this.

Thanks

Do you mean the DNA concentration in the sample or of your PCR product?
I would spec it (if the DNA sample) or use a small mass quantification ladder on an agarose gel (for the amplicon) to quantify the concentration.