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PHASiFY ENRICH cfDNA Extraction Kit

PHASiFY ENRICH cfDNA Extraction Kit

The PHASiFY ENRICH cfDNA Extraction Kit is designed for maximum yield of cfDNA from plasma and superior enrichment of cfDNA by size selection.

  • For research use only.
PHASiFY ENRICH cfDNA Extraction Kit



  • High Yield and Concentration: Multiple-fold increase in cell-free DNA recovery with flexible elution volume 
  • High Purification: Removal of contaminating genomic DNA, without loss to target cfDNA 
  • Enrichment by Size Selection: Removal of >500 bp high molecular weight DNA 
  • Modifiable Size Selection: Contact us to discuss custom solutions    




ApplicationsddPCR, PCR, real-time PCR, NGS, other 
Sample typePlasma 
Time per run ~210 mins
Input volume1 mL, 2 mL  
Elution volume5 µL - 150µL 
Shelf life stability12 months 
Intended useResearch use only (RUO)
Shipping conditionRoom temperature
Storage condition

RT Box: Stored at 15-30°C 

COLD Box: Stored at 4°C 





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Figure 1- Improved yield of circulating tumor DNA (ctDNA) 


The cfDNA was extracted from 28 tissue-positive cancer patient plasma samples (1 mL) using PHASiFY ENRICH and the QIAamp CNA kit. On average PHASiFY ENRICH demonstrated a 2.5-fold increase in mutant copy recovery compared to QIAamp CNA (P-Value <0.01 Wilcoxon Signed-Rank). 




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Figure 2 – Enrichment of cfDNA fragments and removal of contaminating genomic DNA 


DNA was extracted from 2 mL healthy human plasma spiked with 100 bp ladder using PHASiFY MAX and PHASiFY ENRICH. Fragment analyzer trace demonstrates significant removal of fragments above 500 bp while maintaining recovery of target cfDNA. 





If you have less plasma input than the volume indicated on the kit, we recommend bringing the sample volume up to the indicated volume by adding 1x PBS (pH 7.4) prior to step 1. However, we do not recommend using less than 80% v/v of plasma. 

A higher volume input might disrupt phase forming. We recommend using the plasma input volume as indicated on the kit. 

Under controlled conditions, the bottom phase will be approximately 800-860 μL for the 1 mL plasma input kit and 900-950 μL for the 2 mL plasma input kit. Regardless of the volume, we recommend extracting all the bottom phase during Step 5. 

This will depend on your downstream application of the extracted DNA. It is possible that any transfer of the wrong phase can impact your results. We have found that transferring 

small amounts (<10% by volume) will not significantly impact results for most applications, however getting extra bottom phase in step 7 would affect performance of size selection. 


We recommend to avoid transfer of the wrong phase in all cases. 

We recommend transferring only the stated volume of the red top phase. Transferring more of the top phase may affect performance of size selection, resulting in poor removal of large fragments. We recommend extracting the specified volume of the top phase. 

You can add another 40% isopropanol wash (i.e. repeat steps 15 and 16) before the 70% ethanol wash to increase the purity of the samples. Note, additional washing steps may reduce DNA recovery/yield. 


PHASiFY ENRICH kit has a gradual removal of DNA sized from 500bp to 1000bp, and complete removal of size above 1000bp. It collects mainly cfDNA monomer, dimer and trimer fragments. 


PHASiFY ENRICH kit can completely remove DNA sized larger than 1000bp, likely the genomic DNA released into plasma. This kit can also remove other common contaminants such as proteins. 


PHASiFY ENRICH kit is tested to perform as comparable as PHASiFY MAX regarding cfDNA yield. PHASiFY MAX is aimed to collect as much DNA, while PHASiFY ENRICH is aimed to remove large-sized DNA in plasma samples.