Revolutionize mNGS with VDOBIOTECH's Cutting-Edge Magnetic Beads, Combatting Microbial Contamination in Nucleic Acid Extraction

The next-generation metagenomic sequencing (mNGS), as a new pathogen detection method, offers a wide range of detection and is capable of identifying bacteria, viruses, fungi, parasites, rare pathogens, and even unknown pathogens. The NGS procedure is unbiased, can obtain all nucleic acid information from a sample rapidly, efficiently, and accurately, and is therefore ideally suited for analyzing pathogenic microorganisms. Especially in cases of challenging infectious diseases, it plays a crucial role in guiding clinical diagnosis and treatment.

In the process of mNGS testing, false positives are often encountered, which may be caused by trace DNA contaminants present in laboratory reagents, centrifuge tubes, or other steps of the experimental workflow leading to DNA contamination. To address the issue of background microbial contamination during the pre-processing of mNGS sequencing samples and meet the needs of customers, VDOBIOTECH provides high-quality magnetic beads for nucleic acid extraction, along with relevant solutions, to eliminate background microbial contamination. This effectively resolves the issue of microbial contamination associated with magnetic beads, thereby avoiding result misinterpretation and enhancing the accuracy of mNGS testing results.

VDOBIOTECH Magnetic Bead Background Bacterial Contamination Removal Scheme Demonstration 

(Example Using MA0308C Magnetic Beads)

1. Background Bacterial Removal Evaluation

Detection Method: To confirm the efficacy of the magnetic bead reagent in the bacterial removal process, the 16S rDNA amplification reagent, is used for detecting residual background bacteria, and the storage solution of the unremoved magnetic beads.

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Conclusion: The results revealed a close similarity between the CT value of the storage solution and that of sterile water following the removal of background bacteria from the magnetic beads. A significant improvement was observed when comparing these results to the pre-treatment findings.

2. Performance Testing of Magnetic Beads for Nucleic Acid Capture After Treatment

Method: 20μL of treated and untreated magnetic beads were used to extract HBV and HCV viral nucleic acids separately, followed by amplification and detection.

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Conclusion: The results of HBV and HCV detection using the treated magnetic beads were found to be satisfactory and comparable to the untreated beads, indicating that the treated magnetic beads themselves remain unaffected and exhibit stable performance.

3. Background bacteria removal was assessed after accelerated aging experiments.

Method: Magnetic beads were subjected to accelerated aging at 45°C for 30 days. The 16S rDNA amplification reagent was used to detect the storage solution of both background bacteria-removed and unremoved magnetic beads, aiming to confirm the presence of residual background bacteria in the original magnetic beads solution.

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Conclusion: Following the background bacteria removal treatment, the CT value of the storage solution for the magnetic beads, even after 30 days of accelerated aging, closely resembled the CT value of the negative control water. This indicates the thorough removal of background bacteria.

4. Performance Testing of Nucleic Acid Capture by Magnetic Beads after Accelerated Aging

Method: 20μL of treated and untreated magnetic beads were used to extract HBV and HCV viral nucleic acids separately, followed by amplification and detection.

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Conclusion: The CT values of the treated magnetic beads were comparable to those of the control beads, indicating that the background bacteria-removed magnetic beads, subjected to 30 days of accelerated aging, exhibited nucleic acid capture efficiency similar to that of the control beads. The performance of the magnetic beads remained unchanged.

Based on the results of the above experiments, it can be concluded that the treated magnetic beads effectively remove background microbial contamination without affecting their performance, ensuring stable nucleic acid capture efficiency.

Product Series: VDOBIOTECH Magnetic Microspheres

Elevate your bioanalysis with VDOBiotech's magnetic microspheres, delivering swift and accurate extraction, purification, and detection of biological samples.

Production Information:

VDOBiotech has developed magnetic microspheres specifically engineered for extracting, purifying, and detecting biological samples.

These microspheres possess a high magnetic content and moderate density, enabling them to exhibit rapid magnetic response speed and exceptional resuspension when subjected to a magnetic field. Moreover, they are highly compatible with various automated instruments, making them suitable for diverse applications.

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The microspheres for extraction and purification:

  • High Magnetic Content

  • Fast Magnetic Response Speed

  • Excellent Resuspension 

  • Core-shell Structure

  • Large Specific Surface Area

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Surface coating Groups:

-COOH -OH-NH2 -SH -Tosyl -Epoxy -Cloromethyl -Streptavidin -Biotin

Core material: Fe3O4/ Silica/ iron oxide

The Magnetic microspheres for detection:

  • coated with streptavidin, known for its robust and specific interaction with Biotin.

The magnetic microspheres manufactured by VDO Biotech are meticulously designed to maintain an extended shelf life when stored under suitable conditions.

Free Sample Offering:

Submit your request and apply for a free sample (1 ml) now. Only 20 free samples! First come, first serve!


1. Han SY. Clinical value of metagenomic next-generation sequencing in complicated infectious diseases. Zhongguo Dang Dai Er Ke Za Zhi. 2022 Feb 15;24(2):210-215. English, Chinese. doi: 10.7499/j.issn.1008-8830.2110064. PMID: 35209988; PMCID: PMC8884048.

2. Chen P, Sun W, He Y. Comparison of metagenomic next-generation sequencing technology, culture and GeneXpert MTB/RIF assay in the diagnosis of tuberculosis[J]. Journal of Thoracic Disease, 2020, 12(8): 4014.

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