new MenuItem(addMenu, SWT.SEPARATOR);
createMenuItem(addMenu, TISSUE_SAMPLE, selectedTreeNode, DnaSample.class, SpecimenOrObservationType.TissueSample, DerivationEventType.PREPARATION());
createMenuItem(addMenu, DNA_SAMPLE, selectedTreeNode, DnaSample.class, SpecimenOrObservationType.DnaSample, DerivationEventType.DNA_EXTRACTION());
new MenuItem(addMenu, SWT.SEPARATOR);
createMenuItem(addMenu, TISSUE_SAMPLE, selectedTreeNode, DnaSample.class, SpecimenOrObservationType.TissueSample, DerivationEventType.PREPARATION());
createMenuItem(addMenu, DNA_SAMPLE, selectedTreeNode, DnaSample.class, SpecimenOrObservationType.DnaSample, DerivationEventType.DNA_EXTRACTION());