def get_reagent_types(self, name=None, start_index=None):
        """Get a list of reqgent types, filtered by keyword arguments.
        name: reagent type  name, or list of names.
        start_index: Page to retrieve; all if None.
        """
        params = self._get_params(name=name,
                                  start_index=start_index)
        return self._get_instances(ReagentType, params=params)