264 results about "Dna concentration" patented technology

Systems, methods, and apparatus for determining at least a portion of fetal genome are provided. DNA fragments from a maternal sample (maternal and fetal DNA) can be analyzed to identify alleles at certain loci. The amounts of DNA fragments of the respective alleles at these loci can be analyzed together to determine relative amounts of the haplotypes for these loci and determine which haplotypes have been inherited from the parental genomes. Loci where the parents are a specific combination of homozygous and heterozygous can be analyzed to determine regions of the fetal genome. Reference haplotypes common in the population can be used along with the analysis of the DNA fragments of the maternal sample to determine the maternal and paternal genomes. Determination of mutations, a fractional fetal DNA concentration in a maternal sample, and a proportion of coverage of a sequencing of the maternal sample can also be provided.

Disclosed are systems and methods for identifying and quantitating the presence of one or more DNA species in a sample population through PCR amplification. DNA species quantitation includes a determination of a threshold fluorescence value used in the assessment of the PCR amplification reaction. Various embodiments of the present invention incorporate an enhancement function useful in selecting appropriate threshold fluorescence values and facilitate the determination of DNA concentrations by quantitative PCR based methodologies.

The transformation yield of electroporation is increased by using higher DNA concentrations and DNA affinity purification. Fusion proteins of a viral coat protein variant and a heterologous polypeptide are useful in phage display systems.

The invention relates to a nicking endonuclease-based netted rolling cycle amplification system and a use thereof. Based on the existing second-generation hyperbranched rolling cycle amplification technology, the amplification system utilizes a special endonuclease which is nicking endonuclease Nb.BsrDI so that a third-generation rolling cycle amplification technology which is a netted rolling cycle amplification (NGCA) technology is produced. Intensity of fluorescence signals produced by the netted rolling cycle amplification is increased with increasing of a target DNA concentration, is obviously stronger than that of fluorescence signals produced by linear rolling cycle amplification and hyperbranched rolling cycle amplification and has a detection limit of 0.1fM. Compared with the first-generation linear rolling cycle amplification and the second-generation hyperbranched rolling cycle amplification, the nicking endonuclease-based netted rolling cycle amplification system retains the prior art advantages in operationality, use cost and amplification time, further realizes signal amplification based on the prior art thereby providing good technical conditions for ultralow-abundance nucleic acid sample analysis and detection, and has a wide application prospect.