Abstract: A microscale affinity purification system has a plurality of capillary channels (100) which begin and end in common compartments (110, 120). An introduction cross-capillary channel (130) runs across the capillary channels (100) in a serpentine pattern (136, 138) near one end and a collection channel (140) similarly crosses the capillaries (100) in a serpentine pattern (148, 150) near the other end. A target molecule is introduced from a reservoir (132) which binds to a desired strong ligand in a sample in the capillaries (100). The target-strong ligand comlex migrates through the capillaries (100), is detected at a detector (146), and <collected in a collection reservoir (144).

Abstract: Disclosed is a method of detecting a single-stranded target oligonucleotide in a biological fluid. In this method, a biological fluid sample to-be-tested is contacted with helper and primer oligonucleotides, thereby forming a labelled, double-stranded molecule if the sample contains an oligonucleotide which is complementary to the nucleotide sequences of the primer and the helper oligonucleotides. The primer so annealed to the target oligonucleotide is then ligated to the helper annealed to the target oligonucleotide. The presence of the ligation product is being indicative of the presence of the target oligonucleotide in the biological fluid.

Abstract: Disclosed is a method for determining the nucleotide sequence of a target oligonucleotide. In this method a single-stranded ligation product is prepared which contains a target oligonucleotide-to-be sequenced and an auxiliary oligonucleotide. A primer complementary to a portion of the auxiliary oligonucleotide and having a label covalently attached thereto is annealed to the auxiliary oligonucleotide portion of the ligation product. The primer is extended with chain-extending nucleoside triphosphates and chain-terminating nucleoside triphosphates in the presence of a polymerase to yield a plurality of primer extension products. These extension products are then separated on the basis of their base length; and the nucleoside sequence of the target oligonucleotide is determined from the mobilities of the primer extension products obtained during their separation.