Xylanase Assay Kit (Azo-Wax) (K-AZOWAX) (2)

How is the Tris Buffer solution prepared for use in the Xylanase Assay Kit (K-AZOWAX)?

I have assayed the Aspergillus xylanase standard with the Xylanase Assay Kit (K-AZOWAX) using the suggested dilution of 1:100 and am getting an OD of only 0.03.