Square and Compasses Square and Compasses The Square and Compasses (or, more correctly, a square and a set of compasses joined together) is the single most identifiable symbol of Freemasonry. Both the square and compasses are architect's tools and are used in Masonic ritual as emblems to teach symbolic lessons. Some Lodges and rituals explain these symbols as lessons in conduct: for example, Duncan's Masonic Monitor of 1866 explains them as: "The square, to square our actions; The compasses, to circumscribe and keep us within bounds with all mankind". However, as Freemasonry is non-dogmatic, there is no general interpretation for these symbols (or
Protein A/G a lesser extent) IgD. Protein A/G also binds to all subclasses of mouse IgG but does not bind mouse IgA, IgM or serum albumin. This allows Protein A/G to be used for purification and detection of mouse monoclonal IgG antibodies, without interference from IgA, IgM and serum albumin. Mouse monoclonal antibodies commonly have a stronger affinity to the chimeric Protein A/G than to either Protein A or Protein G. Protein A/G also has been used for purification of macaque IgG. In addition to Protein A/G, other immunoglobulin-binding bacterial proteins such as Protein A, Protein G and Protein L are all