1、Neutralizing Antibody Detection - The Gold Standard for HPV Vaccine Evaluation

For detecting neutralizing antibodies against HPV, DIFF Biotech adopts the gold standard method recommended by the World Health Organization (WHO) in the "Guidelines for the Evaluation of Quality, Safety, and Efficacy of HPV VLP Vaccines" - the PBNA method (pseudovirus-based neutralization assay). Neutralizing antibodies specifically recognize antigenic neutralization sites on the viral surface, preventing viral entry and replication, thereby protecting the host from harm. They have actual antiviral activity and serve as an indicator for evaluating immune effectiveness.

Figure 1.Results of Neutralizing Antibody Detection Using DIFF-HPV Pseudovirus

CC: Cell control group; VC: Pseudovirus control group; 1/160, 1/640, 1/2560 represent serum dilution factors.

As shown in the above figure (Figure 1), the DIFF-HPV pseudovirus neutralization antibody detection results indicate that the ID50 of the HPV antisera sample against type 33 is 1800, and against type 18 is 4266. At a dilution of 1/160, the antisera can completely neutralize both types of DIFF-HPV pseudoviruses.

2、Product catalog

3、Product Features

1.High Signal-to-Noise Ratio

When detecting serum neutralizing antibodies under the same excitation light intensity, DIFF-HPV pseudovirus shows a high fluorescence signal intensity and a transparent  background, with fluorescence spots visible to the naked eye.  Compared to similar products in the market, it has higher and stronger performance indicators.

Compared to similar products in the market, it has higher and stronger performance indicators.

2.High Stability

Stable through 5 freeze-thaw cycles (validated by infectivity assays)does not affect product performance. Testing has shown that DIFF-HPV pseudovirus performance remains unaffected after up to 5 freeze-thaw cycles.

3.Ease of Cultivation

DIFF-HPV pseudovirus only requires cultivation in 293T cells. 293T cells (human embryonic kidney cells) are a cell line derived from 293 cells through genetic engineering. They are a common mammalian cell line and produce high-titer viruses when used for retrovirus production. Compared to other cell lines, 293T cells offer great convenience and availability.

4、Application Scope of DIFF HPV Pseudoviruses

• Suitable for detecting neutralizing antibody titers in anti-HPV sera, monoclonal antibodies, and other samples;

• For in vitro efficacy evaluation of HPV-targeting antivirals (targeting L1 and L2 as the target).

五、Case Study DIFF-HPV Pseudovirion Sera Neutralization Titration Curve

Using DIFF-HPV pseudovirions of different types exclusively developed by DIFF Biotech for serum neutralization titration detection, the diagram of the 50% neutralization titer (NT50) is shown below (Figure 2, Figure 3, Figure 4):

Figure 2. Neutrality of HPV16 using DIFF-HPV16-RFP pseudo virus detection serum against HPV16

Figure 3. Neutrality of HPV45 using DIFF-HPV45-BFP pseudovirus detection serum against HPV45

Figure 4. Neutrality of HPV31 using DIFF-HPV31-GFP pseudovirus detection serum against HPV31

六、DIFF-HPV Pseudovirus Operation Guide

The supporting experimental method developed by DIFF Biotech has improved the convenience of operation, It can simultaneously detect 9 different types of HPV neutralizing antibodies on a 96-well plate, reducing the repetitive labor of experimental personnel and improving experimental efficiency.

Please refer to the Product Manual for details.

七、Excellent service experience

Digitalized Management:: We provide project-based scientific research services and information-based experimental processes.

Technical advantage: We have world-leading recombinant virus vector technology and hold more than 50 domestic and foreign invention patents.

Quality assurance: We have established a quality management system that complies with ISO9001 standards to ensure the authenticity and reliability of data.

Service philosophy: We cherish every opportunity for cooperation, focus on customer needs, ensure data security, and are trustworthy experts in biological research delivery.