Abstract: Double hybrid or multihybrid probes and compositions are usefully combined with capture assay and immobilization to provide for detection processes in which target polynucleotides can be detected or the presence or absence of genetic mutations or defects in genetic material can be determined. The capture assay involves capturing a hybrid structure, e.g., single hybrid, double hybrid or multihybrid, or capturing a complex formed by reacting a hybrid structure with a complex forming moiety, e.g., protein, such as a binding protein including an antibody. Immobilization can also be employed prior to hybridization or complexation in which instance a polynucleotide probe can be fixed to a matrix or solid support, e.g., natural or synthetic. Capture and immobilization can be carried out using direct and indirect binding and attachment techniques. Targets can be detected directly or indirectly by using a signal generating moiety and labels.