Human Complement, Single Donor, IgG Depleted
Human serum is depleted of IgG antibodies, 0.2 µm filtered, aliquoted and frozen.Often used as the complement source in human serum bactericidal assays (hSBA).
Specifications
Physical State:
Frozen Liquid
Storage:
-70°C or below
Release criteria
Residual IgG:
< 10%
Lead time on this item is currently: 2-4 Weeks
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Product Overview
| Species: | Human |
|---|---|
| Product Types: | Complement |
| Source: | OTC Serum (Complement Preserved) |
| Pooling: | Single Donor |
| Donor Sex: | Mixed |
| Depletion Process: | IgG Depleted |
| Physical State: | Frozen Liquid |
| Application Notes: | Suitable for functional antibody assays (SBA-Serum Bactericidal Assay, MOPA/OPA- Multiplexed /Opsonophagocytic Killing Assay) for vaccine evaluation. Complement components are extremely heat-sensitive; for best results, thaw complement on ice or in a cold water bath. Aliquots may be made and frozen at -70°C or below. Avoid multiple freeze-thaw cycles. When a working aliquot is thawed, do not re-freeze remaining complement, but discard it. |
| Testing: | CH50: Report Residual IgG: <10% Serum tested negative for infectious disease per FDA guidelines. |
| Storage Conditions: | -70°C or below |
| Shipping Conditions: | Dry ice |
| Packaging: | Cryovial, Poly bottle |
| Expiration: | 1 year from date of receipt when stored continuously at -70°C or below; avoid repeated freeze/thaw. Product quality is guaranteed to meet Pel-Freez Biologicals' specifications for this period when stored as indicated. |
Product Applications
- Serum bactericidal assay
- Opsonophagocytic assay
- Complement-dependent cytotoxicity
- Hemolytic complement assay
- Assay diluent & negative matrix
- Assay controls & calibrators
- Toxicology assays
- Vaccine development
- In vitro diagnostics
Documents & Datasheets
Certificate of Analysis
| Lot | Issued | |
|---|---|---|
| 22846-3701 | Sep 25, 2024 | Download |
| 23246-3695 | Sep 25, 2024 | Download |
| 23246-3701 | Sep 25, 2024 | Download |
| 22846-3697 | Sep 25, 2024 | Download |
| 22846-9769 | Sep 25, 2024 | Download |
| 23246-3684 | Sep 25, 2024 | Download |
| 22746-2157 | Aug 30, 2024 | Download |
| 22746-9786 | Aug 30, 2024 | Download |
| 22646-9738 | Aug 30, 2024 | Download |
| 22646-9749 | Aug 30, 2024 | Download |
Frequently Asked Questions
How does freezing and thawing affect complement activity?
Multiple freeze-thaw cycles will result in reduced complement potency, so we offer a variety of pack sizes to satisfy applications ranging from small scale assay development experiments to large scale clinical studies. We recommend limiting the number of freeze-thaw cycles and sub-aliquot into single-use quantities whenever possible in order to extend the shelf life of all of our complement products.
Should I choose lyophilized or frozen liquid complement?
We offer baby rabbit and human complement in both forms. Frozen liquid complement is ready to use after thawing and is stored at -70°C or below. Lyophilized complement is stored at -20°C or below, is easier to ship, and is reconstituted with sterile water to the label volume, or to a smaller volume when you need higher potency.
What is complement activity (CH50 / hemolytic titer) and how is it tested?
The hemolytic titer measures how well complement lyses antibody-sensitized sheep red blood cells; CH50 is the dilution of serum that lyses 50% of the cells. It is the release test for every lot of our complement products, and our heat-inactivated human products are CH50 tested to confirm that complement activity is absent.
Should I use human, rabbit, or guinea pig complement for my application?
Work backwards from the readout. Complement regulators are host-specific, so the complement source is part of the assay method, not a preference.
- Antibody-depleted human complement for the hSBA (serogroup B meningococcus and gonococcus; correlate hSBA ≥ 1:4). Neisseria recruits human factor H, which rabbit and guinea pig factor H cannot replace, and the donor antibodies in native human serum would kill the target on their own.
- Baby rabbit complement for the rSBA (serogroups A, C, W and Y; correlate rSBA ≥ 1:8) and for pneumococcal OPA/MOPA, which was standardized on it.
- Adult rabbit complement for complement-dependent cytotoxicity and HLA crossmatching, the classical cell-lysis source.
- Guinea pig complement where potency per volume is the point: CH50 titration, complement fixation and the vibriocidal assay.
When the model animal's own cascade is the readout, use matched-species complement. Mouse, rat, pig, canine, cynomolgus, goat and hamster complement are available on request through our custom quote form.
For what the research literature actually uses, by pathogen and assay, see which complement source for which assay.
What concentration of human complement should I use?
The ideal concentration of complement used in SBAs and OPKAs will vary with the specific pathogen and assay conditions. Typical concentrations range from 10-25%.
Why am I seeing non-specific killing in my opsonophagocytic killing assay?
Endogenous complement activity can cause intrinsic, non-specific bacterial killing. We recommend preventing this by heat-inactivating all OPA/OPKA antisera at 56°C for 30 minutes, and always running controls of complement, HL60 cells and bacteria without antiserum to assess non-specific killing. If you are still seeing higher than expected non-specific killing, try the following:
• Run the assay with a new aliquot of bacteria, in case the original was compromised in a way that made it easier to kill.
• Use a different bacterial strain to see if you can replicate the finding.
• Test a new HL60 cell preparation, preferably at a higher or lower passage number.
• Run the assay with a new aliquot of bacteria, in case the original was compromised in a way that made it easier to kill.
• Use a different bacterial strain to see if you can replicate the finding.
• Test a new HL60 cell preparation, preferably at a higher or lower passage number.
Show 9 more questions
How is Pel-Freez Biologicals' antibody-depleted complement made?
We have developed a proprietary process for antibody removal based on affinity chromatography. It removes the immunoglobulins while maintaining high complement potency; the residual-antibody specification is given in the next question.
What's the difference between antibody-depleted human complement (ADHC), heat-inactivated ADHC (ADHC-HI) and antibody-depleted human serum (ADHS)?
- ADHC (antibody-depleted human complement) keeps high complement potency for assays that need functional complement.
- ADHC-HI is the same material heat-inactivated and CH50 tested to confirm no complement activity, for applications that need the other serum components but not complement.
- ADHS (antibody-depleted human serum) starts from normal human serum that was not collected to preserve complement; it is neither heat-inactivated nor CH50 tested, and serves as a negative matrix for dilution, QC samples, or cell culture where complement would inhibit growth.
Which immunoglobulins are removed from your antibody-depleted human products?
We offer IgG-depleted, IgG/IgM-depleted and IgG/IgM/IgA-depleted versions of both our human complement and our human serum, all made by the same affinity chromatography process. Match the depletion to the isotypes your assay detects.
Are there residual antibodies in Pel-Freez Biologicals' antibody-depleted complement?
Our specification for residual antibody in antibody-depleted products is <3.5% of the feed serum for each isotype. Typical residual IgG is <2% and IgM is usually undetectable after depletion. Because assay conditions vary widely, many customers sample one or more lots to confirm they suit their specific system.
Is complement activity affected by the antibody removal process?
Antibody removal can lower complement potency in hemolytic titer assays; our process is optimized to limit that loss. Every lot is tested by the complement hemolytic titer assay at 50% dilution to confirm adequate functional activity.
What's the maximum lot size of antibody-depleted human complement (ADHC) that I can order?
We are proud to serve our customers by offering ADHC lot sizes in excess of 5 L.
What is the difference between pooled and single-donor products?
Pooled products combine material from multiple donors, which averages out donor-to-donor variation and gives large, uniform lots. Single-donor products come from one donor: their properties trace to that donor and can differ more between lots. Studies that need a single, well-characterized source, such as one complement lot carried through a clinical trial, use single-donor material.
What is human complement used for in meningococcal and gonococcal vaccine research?
Human complement is the required complement source for the hSBA, the serum bactericidal assay used to evaluate serogroup B meningococcal vaccines such as 4CMenB and MenB-fHbp and the pentavalent MenABCWY vaccines. Neisseria binds human factor H to evade human complement, an interaction rabbit complement does not reproduce. Publications citing our human complement also cover Neisseria gonorrhoeae bactericidal assays and vaccine candidates, native outer membrane vesicle vaccines, and factor H and NspA binding studies.
Why do published hSBA methods use antibody-depleted human complement?
Human sera almost always contain natural antibodies to Neisseria and other bacteria, so untreated human complement kills the target strain on its own and cannot serve as an exogenous complement source. IgG/IgM-depleted human complement (34010 pooled, 34013 single donor) keeps the complement activity while removing those antibodies, which is why standardized hSBA methods for MenB and gonococcal vaccines specify it.
Product References
- Salic acid protects nontypeable Haemophilus influenza from natural IgM and promotes survival in murine respiratory tract.
Jackson, M. D., Wong, S. M. & Akerley, B. J. Sialic acid protects nontypeable haemophilus influenzae from natural igm and promotes survival in murine respiratory tract. Infect. Immun. 89, (2021).
- Development of Complement Factor H–Based Immunotherapeutic Molecules in Tobacco Plants Against Multidrug-Resistant Neisseria gonorrhoeae
Shaughnessy, J. et al. Development of Complement Factor H–Based Immunotherapeutic Molecules in Tobacco Plants Against Multidrug-Resistant Neisseria gonorrhoeae. Front. Immunol. 11, 2680 (2020).
- Synthetic DNA Delivery of an Optimized and Engineered Monoclonal Antibody Provides Rapid and Prolonged Protection against Experimental Gonococcal Infection
Parzych, E. M. et al. Synthetic dna delivery of an optimized and engineered monoclonal antibody provides rapid and prolonged protection against experimental gonococcal infection. MBio 12, 1–13 (2021).
- Neisseria meningitidis urethritis outbreak isolates express a novel factor H binding protein variant that is a potential target of group B-directed meningococcal (MenB) …
Tzeng, Y. L. et al. Neisseria meningitidis urethritis outbreak isolates express a novel factor H binding protein variant that is a potential target of group B-Directed meningococcal (menb) vaccines. Infect. Immun. 88, (2020).
- Vaccination with Detoxified Leukocidin AB Reduces Bacterial Load in a Staphylococcus aureus Minipig Deep Surgical Wound Infection Model
Fernandez, J. et al. Vaccination with Detoxified Leukocidin AB Reduces Bacterial Load in a Staphylococcus aureus Minipig Deep Surgical Wound Infection Model . J. Infect. Dis. (2021).
- Preclinical efficacy of a lipooligosaccharide peptide mimic candidate gonococcal vaccine
Gulati, S. et al. Preclinical efficacy of a lipooligosaccharide peptide mimic candidate Gonococcal vaccine. MBio 10, (2019).
- Complement-Dependent Serum Bactericidal Assays for Neisseria gonorrhoeae
Gulati, S., Rice, P. A. & Ram, S. Complement-Dependent Serum Bactericidal Assays for Neisseria gonorrhoeae. in Methods in Molecular Biology vol. 1997 267–280 (Humana Press Inc., 2019).
- Development of Complement Factor H–Based Immunotherapeutic Molecules in Tobacco Plants Against Multidrug-Resistant Neisseria
Shaughnessy, J. et al. Development of Complement Factor H–Based Immunotherapeutic Molecules in Tobacco Plants Against Multidrug-Resistant Neisseria gonorrhoeae. Front. Immunol. 11, (2020).
Alternate Names
Human Complement Serum
