It all depends at what you want to detect
Looking for DNA, then you need a complementary DNA probe (South)
Looking for RNA, then you need a complementary DNA probe (North)
Looking for Protein, then u need a binding antibody (West)
Looking of DNA binding protein, then u need a DNA probe (Southwest)
Looking for DNA, then you need a complementary DNA probe (South)
Looking for RNA, then you need a complementary DNA probe (North)
Looking for Protein, then u need a binding antibody (West)
Looking of DNA binding protein, then u need a DNA probe (Southwest)