whereas the anticoagulant activity of heparins , as measured by usp , anti-xa , and thrombin-time assays , was invariably reduced by the chemical transformations effected , the ability of heparin to bind calcium ions was found to be dependent on retention of the 2-sulfamino group , whether or not o-sulfate groups were present .
C0019139
anti-xa
C0019134
heparin