passages.id: split_4_test_1455_passage
passages.type: progene_text
passages.text: A molecular typing method based on polymerase chain reaction ( PCR ) amplification of three different target domains ( immunoglobulin domains 1 and 3 , and the transmembrane - cytoplasmic domain ) , followed by hybridisation with 26 digoxigenin - labelled sequence - specific oligonucleotide probes ( SSOP ) has been established for the polymorphic killer inhibitory receptor ( KIR ) genes .