we describe and validate an assay for 1 to 10 microl rat and human serum or plasma using 5 mm hip-his-leu in 500 microl of 0.4 m sodium borate buffer , ph 8.3 , containing 0.9 m nac1 at 37 degrees c that reduced the subestimation error to less than or equal to 3 % ( rat serum ) and less than or equal to 0.1 % ( human serum ) and increased the ace activity twofold to threefold .
C0032105
plasma
C0229671
serum