Fusion gene amplification results by Fout-S/Fout-AS primers; M= Molecular size marker; 1= Negative Control (H2O), 2 = NDV/Ck/Bogor/011; 3= NDV/Ck/GnSindur/014; 4 = NDV/Ck/Cianjur/015; 5 = NDV/Ck/Bogor/015