NH-bis(PEG4-Propargyl) is a bifunctional PEG compound containing two terminal alkynes that are joined together at a secondary amine. Terminal alkynes are reactive towards azides in copper (I) click chemistry to form stable triazoles with the target compound. The secondary amine joining the two arms can be used as a nucleophile such as in alkylation via reductive amination or in forming amides with carboxylic acids or activated NHS esters. The use of a central amine also allows for hydrogen bonding, further increasing this compound’s water solubility.
NH-bis(PEG4-Propargyl) is a bifunctional PEG compound containing two terminal alkynes that are joined together at a secondary amine. Terminal alkynes are reactive towards azides in copper (I) click chemistry to form stable triazoles with the target compound. The secondary amine joining the two arms can be used as a nucleophile such as in alkylation via reductive amination or in forming amides with carboxylic acids or activated NHS esters. The use of a central amine also allows for hydrogen bonding, further increasing this compound’s water solubility.
The series of DNA Size Selection Kits (Magnetic Beads) were developed for DNA size selection using magnetic beads. A total of 11 kits are available, with different selection ranges spanning from 50 bp to over 10 kb. The kits provide a simple and quick approach for the enrichment of a specific range of DNA fragments. The kit workflow allows double-sided or single-sided size selection for specific size cutoffs.
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DNA size selection is a selective capture of DNA fragments of a specific range of size for next-generation sequencing (NGS) library preparations, PCR, ChIP assay, DNA ligations, endonuclease digestions, adapter removal, and other genomics and molecular biology applications. DNA size selection is preferred after NGS library prep in most of the cases. The NGS library preparation is related to the quality of the sequencing data. Precise NGS library size selection can increase sequencing efficiency, improve data quality, and reduce costs.
There are two types of sequencing technologies: short-read sequencing and long-read sequencing. Short-read sequencing uses DNA libraries that contain small insert DNA fragments of similar sizes, usually several hundred base pairs. The sequencing efficiency can be improved if the DNA size selection is in the right range. Cat.# 20104S and 20104L are the best kits for NGS library size selection of illumina paired-end 100 (PE100) sequencing with 100-200 bp library inserts; Cat.# 20105S and 20105L are the best kits for NGS library size selection of illumina paired-end 150 (PE150) sequencing with 150-300 bp library inserts; and Cat.# 20106S and 20106L are the best kits for NGS library size selection of illumina paired-end 300 (PE300) sequencing with 300-600 bp library inserts.
Long-read sequencing uses a large DNA fragment as input and makes very long reads. Usually, library size selection is preferred to remove smaller fragments. Cat.# 20110S and 20110L are the best kits for long-read sequencing size selection with DNA sizes >5 kb, and Cat.# 20111S and 20111L are the best kits for long-read sequencing size selection with DNA sizes >10 kb.
The magnetic beads technology uses paramagnetic particles, also known as SPRI (Solid Phase Reversible Immobilization) beads, to bind DNA reversibly and selectively. DNA fragments can be size-selected and purified by changing the properties of the magnetic beads or SPRI beads. The magnetic beads can easily separate the beads-binding DNA from the contaminants and unwanted components in the samples. The samples after DNA size selection are free of contaminants such as buffer components, enzymes, proteins, salts, dNTPs, primers, and adapters. Our proprietary magnetic beads reagents improve yield, selectivity, and reproducibility.
Specific DNA fragments at a certain length range can be purified simply using magnetic separation with different beads components, avoiding tedious and time-consuming gel extraction and column-based purification. The magnetic beads method is popular for common DNA size selection, including library size selection. The first beads-binding step, referred to as the right-side clean-up, removes large DNA fragments. The large DNA fragments are bound to the beads and are discarded. The desired DNA fragments in the supernatant are transferred to a new well, and new beads are added to the supernatant for the second beads-binding, referred to as the left-side clean-up. The double-size selected DNA fragments are eluted after ethanol rinsing.
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A single clean-up is needed for DNA size selection with large fragments. In this case, only the large DNA fragments are bound to the beads. The selected larger DNA fragments are eluted after ethanol rinsing.
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