The concentration and volume of this product vary from lot to lot. The protein content and activity of this enzyme are reported on the lot specific Certificate of Analysis. The volume may be calculated using this information. For example, a given lot that reports a protein content of 1 mg/mL and an activity of 300 units per milligram protein, will have a volume of 167 uL. Please see the link below to review a sample or lot specific Certificate:
https://www.sigmaaldrich.com/US/en/product/sigma/s9396#product-documentation
Please see the following link to review the product datasheet:
https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/documents/318/230/s9396dat.pdf