The cfDNA Purification Kit (Magnetic Beads) was developed for cell free DNA (cfDNA) enrichment by separating genomic DNA contamination from isolated cfDNA samples.
Many diagnostic technologies for detection of disease signals in cfDNA begin with isolation and purification of DNA from liquid biopsy that include urine, plasma, cerebrospinal fluid. The most widely explored biotechnology is assays used to detect cancer-derived plasma cfDNA. Silica-based magnetic bead cfDNA isolation kits can reliably extract total DNA from plasma, but typically yield a large variation in cfDNA that includes the presence of genomic DNA that often depends on tumor stage, tumor size, or healthy status individuals. Most of the commercial cfDNA isolation kits can’t specifically recover the cfDNA while leaving the high molecular weight genomic DNA behind. The presence of genomic DNA can lead to decreased sensitivity or inconsistent results in downstream applications such as next-generation sequencing (NGS), PCR, QPCR, and digital PCR etc.
Therefore, an additional purification step to enrich cfDNA before downstream methods helps to improve signal from fragments that originate from cancer cells. A proportion of cancer-derived cfDNA fragment signals are below 100 bp and are often not detectable except by qPCR or single-stranded DNA based library preparation for NGS (1, 2, 3). Furthermore only 1% of cancer-derived fragments are found above 400 bp (1, 2). Capture of size-selected fragments between 90-150 bp improved detection of cancer by 2-4 fold (4). Furthermore, TF-bound and protected cfDNA fragments are also being investigated for active cancer-specific signals down to 35-80 bp (5, 6).
This kit uses Dual Solid Phase Reversible Immobilization (SPRI) technology for cfDNA purification. Most Dual SPRI procedures do NOT recover fragments below 100 bp. The kit can be used for the enrichment of cfDNA isolated from liquid biopsies, plasma, serum, and urine. The kit separates cfDNA (50-500 bp) and genomic DNA, and recovers of 90% of the cfDNA without the high molecular weight genomic DNA with high efficiency. Fragments at 500 bp and above may also be retained. Both the 50-500 bp and >500 bp DNA fractions can be used for downstream applications such as single-stranded or double stranded NGS library prep, qPCR, ddPCR, and other methods.
Features
Examples of cfDNA purification. Both cfDNA and genomic DNA can be recovered separately.
The range of recovered small DNA fragments is from 50 to 500 bp. The input DNA are mixtures of sheared small DNA fragments and intact genomic DNA. The ratios of sheared DNA fragments versus genomic DNA are indicated.
Recovery rates of cfDNA and genomic DNA.
Many diagnostic technologies for detection of disease signals in cfDNA begin with isolation and purification of DNA from liquid biopsy that include urine, plasma, cerebrospinal fluid. The most widely explored biotechnology is assays used to detect cancer-derived plasma cfDNA. Silica-based magnetic bead cfDNA isolation kits can reliably extract total DNA from plasma, but typically yield a large variation in cfDNA that includes the presence of genomic DNA that often depends on tumor stage, tumor size, or healthy status individuals. Most of the commercial cfDNA isolation kits can’t specifically recover the cfDNA while leaving the high molecular weight genomic DNA behind. The presence of genomic DNA can lead to decreased sensitivity or inconsistent results in downstream applications such as next-generation sequencing (NGS), PCR, QPCR, and digital PCR etc.
Usages:
For isolation and enumeration of coagulase-positive staphylococci in foodstuffs.
Principle:
Tryptone, beef extract powder and yeast extract powder provides carbon and nitrogen sources, vitamins and growth factors; sodium pyruvate and glycine to stimulate the growth of Staphylococcus aureus; lithium chloride and potassium tellurite inhibit the non-staphylococcal microorganisms; containing lecithinase staphylococcal colonies produce degradation yolk make transparent circle, while the role of the lipase produced an opaque precipitate ring; coagulase-positive staphylococci can restore potassium tellurite and produce black colonies; agar is medium coagulant.
Formulation（per liter）:
Pancreatic Digest of Casein 10g
Beef Extract 5g
Yeast Extract 1g
Sodium Pyruvate 10g
Glycine 12g
Lithium Chloride 5g
Agar 20g
Final pH7.0 ± 0.2
How to use：
1.Suspend 63g in 950ML of distilled water , stirring heated to boiling ,autoclave at 121℃ for 15 minutes.
2.Diluted and treated samples.
Quality control：
| Item | The name and number of strain | Growth | Colony Color |
| 1 | Staphylococcus aureus ATCC6538 | Good | black |
| 2 | Staphylococcus epidermidis CMCC (B) 26069 | Good | Green-blue |
| 3 | Escherichia coli ATCC25922 | Not growth | — |
Storage: Keep container tightly closed, store in a cool, dry place, away from bright light. Storage period of 3 years.
Specifications: 250g/bottle
*Supplement: 029190 Egg Yolk Tellurite Emulsion
250g
t-Boc-aminooxy-PEG1-propargyl is a click chemistry PEG linker with a t-Boc-aminooxy group. The propargyl group can react with azide-bearing compounds or biomolecules via copper catalyzed azide-alkyne Click Chemistry to yield a stable triazole linkage. The t-Boc aminooxy group can be deprotected under mild acidic conditions and then can react with an aldehyde or ketone group to form a stable oxime linkage. The hydrophilic PEG spacer increases solubility in aqueous media. Reagent grade, for research purpose. Please contact us for GMP-grade inquiries.
t-Boc-aminooxy-PEG1-propargyl is a click chemistry PEG linker with a t-Boc-aminooxy group. The propargyl group can react with azide-bearing compounds or biomolecules via copper catalyzed azide-alkyne Click Chemistry to yield a stable triazole linkage. The t-Boc aminooxy group can be deprotected under mild acidic conditions and then can react with an aldehyde or ketone group to form a stable oxime linkage. The hydrophilic PEG spacer increases solubility in aqueous media. Reagent grade, for research purpose. Please contact us for GMP-grade inquiries.