Abstract: The invention provides a process for synthesizing genes and other long double stranded polynucleotides by assembling very short oligonucleotides into partly double stranded polynucleotides, and then connecting these partly double stranded polynucleotide subassemblies with linkers comprised of very short oligonucleotides. In one embodiment, the correct order of the polynucleotide subassemblies is coded in overhangs present at each end of the partly double stranded polynucleotide subassemblies. Linkers having a sequence complimentary to the combined overhangs connect adjacent subassemblies, which are then ligated together. In one preferred embodiment the oligos are six bases long, for which there are only 4096 different possible sequence permutations. A complete library of oligos of this size and scale can be cost-effectively synthesized and quality controlled, avoiding the typical errors and yield issues associated with phosphoramidite synthesis of longer oligos.

Abstract: It is one objective of the present invention to obtain reproducible representations of expressed mRNA molecules by exploiting a novel technique that relies on short, single stranded polynucleotide tags. In one preferred embodiment, only one polynucleotide tag is obtained from each mRNA molecule, and relatively simple counting statistics can thus be applied after identification and sampling of the different tags, or a subset of tags being present in the population of representative tags. The tags according to the present invention are preferably single stranded polynucleotide tags obtained by subjecting genetic material derived from a biological sample to at least one site-specific nicking endonuclease capable of i) recognizing a predetermined nucleotide motif comprising complementary nucleotide strands and ii) cleaving only one of said complementary strands in the process of generating the at least one single stranded polynucleotide tag.

Abstract: It is one objective of the present invention to obtain reproducible representations of expressed mRNA molecules by exploiting a novel technique that relies on short, single stranded polynucleotide tags. In one preferred embodiment, only one polynucleotide tag is obtained from each mRNA molecule, and relatively simple counting statistics can thus be applied after identification and sampling of the different tags, or a subset of tags being present in the population of representative tags. The tags according to the present invention are preferably single stranded polynucleotide tags obtained by subjecting genetic material derived from a biological sample to at least one site-specific nicking endonuclease capable of i) recognizing a predetermined nucleotide motif comprising complementary nucleotide strands and ii) cleaving only one of said complementary strands in the process of generating the at least one single stranded polynucleotide tag.