where superscript M denotes a 2 0 -O-methyl sugar, N is A, C, G, or U with a 2 0 -O-methyl or LNA sugar, r denotes ribose sugars, and Q is the Watson-Crick complement to N. As summarized in Table 1 , 5 0 terminal LNA substitutions make duplex stability more favorable by 0.3-0.6 kcal/mol at 37 C with an average enhancement of 0.45 kcal/mol. Thus, 5 0 terminal LNA substitutions increase the binding constant for duplex formation by $2-fold at 37 C.