Baby Rabbit Complement

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1. 2025Rosen et al. (2025). International Journal of Infectious Diseases.

   Divergent humoral immune signatures in response to Klebsiella pneumoniae bacteremia

   Where the paper cites Pel-Freez

   …combined with 20 µl of heat-inactivated human serum (inactivated at 56°C for 30 minutes) in 96-well U-bottom plates and incubated shaking at 37°C for 1 h. Subsequently, 10 µl of baby rabbit complement (Pel-Freez Biologics) was added to a final concentration of 10%, and plates were incubated shaking for 1 h at 37°C. All samples were tested in triplicate. Controls included bacteria alone, bacteria with serum only,…

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2. 2025Buisman et al. (2025). npj Vaccines.

   Immunogenicity of primary and booster MenACWY-TT vaccination in older adults and the importance of IgM

   Where the paper cites Pel-Freez

   …Frailty Indicator self-report questionnaire35. Serological analysis Functional MenACWY-specific antibody titers were determined using the serum bactericidal assay with baby rabbit complement (rSBA) (Pelfreez, lot: 21044-C) as described previously15,36. Target strains included MenA (strain 3125), MenC (strain C11), MenW (strain MP01240070), and MenY (strain S-1975). rSBA titers were expressed as the reciprocal…

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3. 2024Ahmad et al. (2024). PLoS ONE.

   Naturally acquired antibodies against 4 Streptococcus pneumoniae serotypes in Pakistani adults with type 2 diabetes mellitus

   Where the paper cites Pel-Freez

   …strains of pneumococcal serotype 19F, 18C, and 9V. Plates were incubated for 30 minutes on a shaker (750 RPM) at room temperature, followed by the addition of 10 μL baby rabbit complement (Pel-freeze biologicals) and differentiated HL-60 cells (cells: bacteria was 200:1). Plates were incubated for another 45 minutes at 37°C in a humidified chamber, followed by cooling on ice for 15 minutes to stop…

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4. 2023Cao et al. (2023). Pharmaceuticals.

   Gamma-Irradiated Non-Capsule Group B Streptococcus Promotes T-Cell Dependent Immunity and Provides a Cross-Protective Reaction

   Where the paper cites Pel-Freez

   …adjusted to 10 5 CFU/mL. Following incubation at room temperature for 30 min with shaking, 40 µL of a differentiated HL-60 cell suspension containing 4 × 10 5 cells and 10 µL baby rabbit complement (BRC; Pel-Freez Biological: Rogers AR) was added. The cell mixture was incubated for 45 min at 37 °C with shaking. Next, 10 µL of the final mixture was spotted onto THY agar containing 1.5% Bacto agar (BD Biosciences).…

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5. 2023Hendriks et al. (2023). Vaccines.

   The Group A Streptococcal Vaccine Candidate VAX-A1 Protects against Group B Streptococcus Infection via Cross-Reactive IgG Targeting Virulence Factor C5a Peptidase

   Where the paper cites Pel-Freez

   …to the manufacturer’s protocol. Neutrophils were adjusted to a concentration of 5 × 10 6 cells/mL in RPMI 1640 tissue culture media, and the bacteria were pre-incubated with baby rabbit complement (PelFreez, #31061) and heat-inactivated fetal bovine serum (FBS, Cat# 97068-085, VWR International). GBS strains were grown to the mid-logarithmic growth phase of OD 600 = ~0.4 and washed twice with sterile…

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6. 2023Zhang et al. (2023). Emerging Microbes & Infections.

   Three neutralizing mAbs induced by MPXV A29L protein recognizing different epitopes act synergistically against orthopoxvirus

   Where the paper cites Pel-Freez

   …assay The neutralizing activity of the mAbs and sera was determined using the MV or EV forms of the VACV Tian tan or WR strain. Neutralization of VACV EV was performed using a 10% baby rabbit complement (Pelfreez). For EV neutralization, MV was depleted with blocking mAbs at 20 mg/mL. BHK-21 cells were maintained in DMEM sup- plemented with 10% calf serum at 37°C, and 5% CO2. On the day of the experiment, BHK-21…

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7. 2022Alugupalli et al. (2022). ImmunoHorizons.

   The Lack of Natural IgM Increases Susceptibility and Impairs Anti-Vi Polysaccharide IgG Responses in a Mouse Model of Typhoid

   Where the paper cites Pel-Freez

   …Ty2 in DPBS (250–500 CFU) was added to each well of a round-bottom polypropylene 96-well plate containing 50 μl of heat-inactivated serum in serial dilutions, 12.5 μl of baby rabbit complement (Pel-Freez Biologicals, Rogers, AR), and 27.5 μl of DPBS. Triplicate samples of each dilution were incubated for 120 min at 37°C with gentle rocking, and 10 μl of this mixture were plated on LB agar plates for counting…

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8. 2021Ozdilek et al. (2021). mBio.

   A Structural Model for the Ligand Binding of Pneumococcal Serotype 3 Capsular Polysaccharide-Specific Protective Antibodies.

   Where the paper cites Pel-Freez

   …and 1% L-glutamine. HL-60 cells were differentiated using 0.6% N,N-dimethylformamide (DMF) for 3 days before performing the OPKA assay, harvested, and resuspended in OBB. Baby rabbit complement (Pel- Freez) was added to HL-60 cells at a 1:5 final volume. The HL-60-complement mixture was added to the bacteria at 5
   105 cells/well. The final reaction mixtures were incubated at 37°C for 1 h with shaking. The…

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9. 2021Gingerich et al. (2021). Infection and Immunity.

   Broadly Reactive Human Monoclonal Antibodies Targeting the Pneumococcal Histidine Triad Protein Protect against Fatal Pneumococcal Infection

   Where the paper cites Pel-Freez

   …were mixed with HBSS as a negative control, and purified human serum IgG was used as a positive control. Differentiated HL-60 cells were washed twice with HBSS and mixed with baby rabbit complement (Pel-Freez Biologicals) at a final concentration of 10% in each well. Following this, 60ml (1
   106 viable cells) of differentiated HL60 cells and complement were added to the mixture of bacteria and antibodies and…

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10. 2021Barreto-Bergter et al. (2021). Glycoconjugate Journal.

    Development and Immunogenicity of a Brazilian Glycoconjugate vaccine against Meningococcal W in a Pilot Scale

    Where the paper cites Pel-Freez

    …Pel-Freez® baby rabbit complement lacking bactericidal activity was added. After incubation 10 µl of the mixture from each well was plated out on Columbia blood agar plate by the tilt…

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11. 2021Paschall et al. (2021). ACS Infectious Diseases.

    Development and Immunogenicity of a Prototype Multivalent Group B Streptococcus Bioconjugate Vaccine

    Where the paper cites Pel-Freez

    …Bio-Rad). The samples were subsequently transferred to nitrocellulose membranes with a 0.2 μm pore size (Bio-Rad… Baby rabbit complement (Pel-Freez) was added to HL-60 cells at a 1…

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12. 2021Sarma et al. (2021). Pathogens.

    Evaluation of Critical Quality Attributes of a Pentavalent (A, C, Y, W, X) Meningococcal Conjugate Vaccine for Global Use

    Where the paper cites Pel-Freez

    …Pathogens 2021, 10, 928 15 of 17 To determine rSBA titers, individual rabbit sera were inactivated at 56 ◦C before initiating the assay. The complement source was 3–4 week old rabbit complement (Pel- freez Biologicals, Rogers, AR, USA). The bacterial strains used in the rSBA assays were: serogroup A, CDC F8238, phenotype A:4:P1.9, O-Acetylation OAc+; serogroup C, strain C11, C:16:P1.7–1,1.1, OAc+; serogroup Y,…

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• Human IgM inhibits the formation of titan-like cells in Cryptococcus neoformans

  Nuria Trevijano-Contador et al. Human IgM inhibits the formation of titan-like cells in cryptococcus neoformans. Infect. Immun. 88, (2020).

• Physicochemical and biological similarity assessment of LBAL, a biosimilar to adalimumab reference product (Humira®)

  Kwon, J.-C. et al. Physicochemical and biological similarity assessment of LBAL, a biosimilar to adalimumab reference product (Humira®). Animal Cells Syst. (Seoul). 1–13 (2021).

• Development of an Opsonophagocytic Killing Assay Using HL-60 Cells for Detection of Functional Antibodies against Streptococcus pyogenes

  Salehi, S., Hohn, C. M., Penfound, T. A. & Dale, J. B. Development of an Opsonophagocytic Killing Assay Using HL-60 Cells for Detection of Functional Antibodies against Streptococcus pyogenes . mSphere 3, (2018).

• Functional Activity of Antibodies Directed towards Flagellin Proteins of Non-Typhoidal Salmonella

  Ramachandran, G. et al. Functional activity of antibodies directed towards Flagellin proteins of non-typhoidal Salmonella. PLoS One 11, 151875 (2016).

• Cryptococcus neoformans Coinfection Dampens the TNF-α Response in HIV-1-Infected Human THP-1 Macrophages

  Kalem, M. C., Humby, M. S., Wohlfert, E. A., Jacobs, A. & Panepinto, J. C. Cryptococcus neoformans Coinfection Dampens the TNF-α Response in HIV-1-Infected Human THP-1 Macrophages. mSphere 6, (2021).

• Investigating the candidacy of the serotype specific rhamnan polysaccharide based glycoconjugates to prevent disease caused by the dental pathogen Streptococcus …

  St. Michael, F. et al. Investigating the candidacy of the serotype specific rhamnan polysaccharide based glycoconjugates to prevent disease caused by the dental pathogen Streptococcus mutans. Glycoconj. J. 35, 53–64 (2018).

• Rational design and evaluation of an artificial Escherichia coli K1 protein vaccine candidate based on the structure of OmpA

  Gu, H. et al. Rational design and evaluation of an artificial Escherichia coli K1 protein vaccine candidate based on the structure of OmpA. Front. Cell. Infect. Microbiol. 8, 172 (2018).

• Immunization with Pseudomonas aeruginosa outer membrane vesicles stimulates protective immunity in mice

  Zhang, X. et al. Immunization with Pseudomonas aeruginosa outer membrane vesicles stimulates protective immunity in mice. Vaccine 36, 1047–1054 (2018).

• Quality improvement of capsular polysaccharide in streptococcus pneumoniae by purification process optimization

  Lee, C. et al. Quality Improvement of Capsular Polysaccharide in Streptococcus pneumoniae by Purification Process Optimization. Front. Bioeng. Biotechnol. 8, (2020).

• Validity of Enzyme-Linked Immunosorbent Assay (ELISA) as a correlate of protection of meningococcal C conjugated vaccine in adolescents with HIV infection

  Daniela Vinhas, B. et al. Validity of Enzyme-Linked Immunosorbent Assay (ELISA) as a correlate of protection of meningococcal C conjugated vaccine in adolescents with HIV infection. J. Vaccines Immunol. 6, 001–007 (2020).

• Age-stratified analysis of serotype-specific baseline immunity against group B streptococcus

  Choi, M. J. et al. Age-stratified analysis of serotype-specific baseline immunity against group B streptococcus. Hum. Vaccines Immunother. 16, 1338–1344 (2020).

• Performance of a Four-Antigen Staphylococcus aureus Vaccine in Preclinical Models of Invasive S. aureus Disease

  Scully, I. L. et al. Performance of a four-antigen staphylococcus aureus vaccine in preclinical models of invasive S. aureus disease. Microorganisms 9, 1–13 (2021).

• A Structural Model for the Ligand Binding of Pneumococcal Serotype 3 Capsular Polysaccharide-Specific Protective Antibodies.

  Ozdilek, A. et al. A Structural Model for the Ligand Binding of Pneumococcal Serotype 3 Capsular Polysaccharide-Specific Protective Antibodies. MBio (2021).

• Opsonophagocytic Antibodies of Intravenous Immunoglobulin Preparations against Seven Streptococcus agalactiae Serotypes

  Lee, J. H., Kim, H. W., Cha, J. & Kim, K. H. Opsonophagocytic antibodies of intravenous immunoglobulin preparations against seven streptococcus agalactiae serotypes. Pediatr. Infect. Vaccine 28, 21–30 (2021).

• An Opsonophagocytic Killing Assay for the Evaluation of Group A Streptococcus Vaccine Antisera

  McGregor, R., Jones, S., Jeremy, R. M., Goldblatt, D. & Moreland, N. J. An Opsonophagocytic Killing Assay for the Evaluation of Group A Streptococcus Vaccine Antisera. in Methods in Molecular Biology vol. 2136 323–335 (Humana Press Inc., 2020).

• Expression of Bordetella pertussis Antigens Fused to Different Vectors and Their Effectiveness as Vaccines

  Xu, H. et al. Expression of bordetella pertussis antigens fused to different vectors and their effectiveness as vaccines. Vaccines 9, (2021).

• Immunogenicity of PCV24, an expanded pneumococcal conjugate vaccine, in adult monkeys and protection in mice.

  McGuinness, D. et al. Immunogenicity of PCV24, an expanded pneumococcal conjugate vaccine, in adult monkeys and protection in mice. Vaccine (2021).

Young Rabbit Complement; 3-4 Week Rabbit Complement; 3-4 Week Old Rabbit Complement; Serum From Baby Rabbits; Pooled Baby Rabbit Serum; Pooled Baby Rabbit Complement