CBI offers a new system for the isolation of circulating nucleic acids (DNA and RNA) from liquid biopsies, cells and tissues. Our DNA isolation kit is based on a new DNA Binding Substance that captures circulating DNA from biofluids (serum, plasma, urine, amniotic and cerebrospinal fluids) without addition of salts and/or chaotropic agents. No Proteinase K digestion is required.  Standard volume of liquid biopsy for DNA isolation is 2-5 ml. Scale up to 50 ml of liquid can easily be done.


We have developed a new method of cell-free DNA (cfDNA) isolation from plasma, serum, and urine samples based on a dual-functional proprietary substance (SubX) that binds DNA under physiological conditions (e.g., directly from biological fluids) where it is absorbed to a solid phase Binding Matrix, e.g. magnetic beads. Current commercial cfDNA isolation kits employ a traditional silica-chaotropic salt approach and often suffer from lot-to-lot surface differences of silica that result in low extraction efficiency of small DNA fragments. Our approach eliminates this problem.

Our DNA isolation procedure includes the following steps:

• DNA binding: simply add SubX and Binding Matrix to your bioliquid sample and rotate for a few minutes;
• Washing: brief vortex-spins;
• Elution: DNA is easily eluted in a small volume (30-50ul) of buffer.


Figure 1. DNA isolation steps. All procedures after mixing plasma or urine with SubX® are done in one tube. Each incubation takes place at room temperature with occasional vortexing. cfDNA is eluted from beads at 65ºC.

Very important tip video: 



Figure 2. DNA yield from 0.2 ml plasma of normal donors and NSCL patients estimated by qPCR for single copy gene 36B4 (A).  cfDNA yield from 1 ml pooled plasma determined by Qubit HS DNA Assay (B).  Protein content in cfDNA Isolated from pooled plasma (C). cfDNA isolated from 4 ml urine samples. DNA was quantified using Qubit HS DNA Assay (D).



Figure 3. Eppstein Barr Virus DNA isolation from B95-8 cell line culture medium. DNA was isolated from 3x1ml aliquots of cell culture S1 and S2. DNA yield was estimated by qPCR with EBV-specific primers and by Qubit HS DNA Assay.

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