Systems and methods for playing a card game are disclosed. In particular, the invention provides a preparation for accelerating an exchange reaction between a nucleotide sequence at specific site of a double stranded DNA or RNA for its homologous nucleotide sequence, the preparation comprising a cationic polymer having a guanidine group-containing main chain and a hydrophilic functional groups as an active ingredient. The guide mechanism reacts between the clamping member and the pivoting arm for moving the pivoting arm between an open position and a closed position.