The present teachings generally relate to methods, kits, and compositions for detecting target polynucleotide sequences. The teachings also relate to ligation and amplification reactions that generate self-complementary polynucleotide products. In some embodiments, ligation reactions are performed with probes that result in the formation a self-complementary ligation product. Ligation of a hairpin linker to the self-complementary ligation product can form a loop ligation product. In some embodiments, the loop ligation product can be amplified with rolling circle amplification. Detection of a loop ligation product can serve to determine the identity of a target polynucleotide.