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GeneTex’s “5 + 1” Pillar Antibody Validation Process

GeneTex’s “5 + 1” Pillar Antibody Validation Process

Figure 1. GeneTex’s “5+1” Pillar Plan for recombinant antibody validation.

 

GeneTex’s production focus is dedicated to the creation of novel recombinant monoclonal antibodies validated using enhanced protocols defined by the International Working Group for Antibody Validation (IWGAV).

Over the last decade, studies published in many of the top scientific journals have clearly described the significant impact of poorly validated antibody reagents on the reproducibility of biomedical research. The unfortunate reality is that the commercial antibody market is compromised by a substantial subset of products that have been demonstrated to be nonspecific. This means that there are two major issues that must be addressed in order to improve the overall quality of the commercial antibody market and therefore the integrity and reproducibility of the biomedical research dependent on antibodies. The first is more widespread adoption of production platforms that emphasize recombinant antibody technology while the second involves incorporation of improved and more coherent validation strategies. GeneTex is making major strides in both of these endeavors.

As was discussed in a prior News feature, GeneTex has already shifted completely to the production of recombinant monoclonal antibodies (Figure 1). Fully recombinant antibodies are defined by their primary sequence, their consistent performance and supply (issues that plague traditional polyclonals and hybridoma-based monoclonals with regard to lot-to-lot variability), and their ability to be engineered (i.e., backbone switching) to meet researcher requirements. The numerous advantages of recombinant antibodies may even evoke more favorable impressions by grant review and journal editorial committees.

In conjunction with the pivot to recombinant antibody production, GeneTex’s second commitment to antibody reliability is its incorporation of enhanced validation protocols, based on the IWGAV proposal mentioned above, into its manufacturing and quality assurance (QA) workflow (1). This involves evaluation of each antibody using at least one, and preferably more, of five validation “pillars” defined in the IWGAV study (1). GeneTex’s version of the IWGAV plan follows the five standard strategies and includes (1) Knockout/Knockdown; (2) Comparable Antibodies; (3) Immunoprecipitation followed by Mass Spectrometry (IP/MS); (4) Biological and Orthogonal Validation; and (5) Recombinant Protein Expression (Figure 1). The company refers to this as its “5+1” Pillar Plan when referencing new recombinant antibody production, with the “+1” designation referring to the pre-validation that is inherent in the application-specific assessment that occurs with clone selection during the recombinant antibody production process (see Validation Examples). With an extensive product catalog, GeneTex is working to replace its traditional polyclonals with new recombinants as well as developing novel antibodies against additional targets. It is also striving to apply IWGAV Five Pillar validation to other products already in the catalog. The task is daunting, but GeneTex is making some progress as noted in a CiteAb blog from October, 2022 (2).

Antibody fidelity, application-dependent reliability, and performance and supply consistency are crucial for ensuring research integrity. GeneTex joins other reputable companies in making antibodies that researchers can trust.

 

Validation Examples

Knockout / Knockdown KOKD-Validation
Complete removal or significant reduction of the endogenous signal following genetic strategies involving genomic editing or RNA interference, respectively.
Integrin beta 1 / CD29 antibody [HL1255] (GTX636657)

Integrin beta 1 / CD29 antibody [HL1255] (GTX636657)

RecombinantKOKD-ValidationComparable AbsOrthogonal ValidationProtein Overexpression
NFkB p105 antibody [HL1784] (GTX637436)

NFkB p105 antibody [HL1784] (GTX637436)

RecombinantKOKD-ValidationOrthogonal Validation
Galectin 3 antibody [HL1878] (GTX637627)

Galectin 3 antibody [HL1878] (GTX637627)

RecombinantKOKD-Validation
ZO-1 antibody [HL1133] (GTX636399)

ZO-1 antibody [HL1133] (GTX636399)

RecombinantKOKD-Validation

 

Comparable antibodies Comparable Abs
Independent antibodies against the same target but to different epitopes, often including distinct samples with different target protein expression levels.
ACE2 antibody [HL1092] (GTX636265)

ACE2 antibody [HL1092] (GTX636265)

RecombinantKOKD-ValidationComparable AbsProtein Overexpression
BrdU antibody [HL1111] (GTX636326)

BrdU antibody [HL1111] (GTX636326)

RecombinantComparable AbsOrthogonal Validation
alpha Synuclein antibody [HL1242] (GTX636641)

alpha Synuclein antibody [HL1242] (GTX636641)

RecombinantComparable AbsOrthogonal Validation
Influenza A virus Nucleoprotein antibody [HL1089] (GTX636247)

Influenza A virus Nucleoprotein antibody [HL1089] (GTX636247)

RecombinantCitation-SupportComparable Abs

 

IP/MS Analysis IP-MS Analysis
Identification of the target protein immunoprecipitated (IP) by the antibody using mass spectrometry (MS) analysis.

 

Biological and orthogonal characteristics Orthogonal Validation
Alterations in the endogenous level of the target protein in accordance with specific preparation conditions corresponding to defined biological characteristics, or comparison between antibody-dependent and -independent methods.
PARP antibody [HL1364] (GTX636804)

PARP antibody [HL1364] (GTX636804)

RecombinantKOKD-ValidationComparable AbsOrthogonal Validation
RAS (G12D Mutant) antibody [HL10] (GTX635362)

RAS (G12D Mutant) antibody [HL10] (GTX635362)

RecombinantCitation-SupportOrthogonal ValidationProtein Overexpression
Bax antibody [HL236] (GTX635715)

Bax antibody [HL236] (GTX635715)

RecombinantKOKD-ValidationOrthogonal Validation
GRK2 (phospho Ser670) antibody [HL1035] (GTX635875)

GRK2 (phospho Ser670) antibody [HL1035] (GTX635875)

RecombinantOrthogonal ValidationProtein Overexpression

 

Protein Overexpression Protein Overexpression
Tagged target proteins expressed in transfected cells are used as the positive control for validation.
Wnt16 antibody [HL1498] (GTX636972)

Wnt16 antibody [HL1498] (GTX636972)

RecombinantProtein Overexpression
AKT1 antibody [HL1142] (GTX636413)

AKT1 antibody [HL1142] (GTX636413)

RecombinantKOKD-ValidationProtein Overexpression
PD-L1 antibody [HL1041] (GTX635975)

PD-L1 antibody [HL1041] (GTX635975)

RecombinantKOKD-ValidationComparable AbsOrthogonal ValidationProtein Overexpression
RAI3 antibody [HL1864] (GTX637589)

RAI3 antibody [HL1864] (GTX637589)

RecombinantOrthogonal ValidationProtein Overexpression

 

Recombinant Antibody Recombinant
Antibody is generated using recombinant technology.
Iba1 antibody [HL22] (GTX635363)

Iba1 antibody [HL22] (GTX635363)

RecombinantComparable AbsOrthogonal Validation
Vimentin antibody [HL1506] (GTX636980)

Vimentin antibody [HL1506] (GTX636980)

RecombinantKOKD-ValidationComparable AbsOrthogonal ValidationProtein Overexpression
EpCAM antibody [HL1339] (GTX636759)

EpCAM antibody [HL1339] (GTX636759)

RecombinantOrthogonal Validation
Gli1 antibody [HL247] (GTX635619)

Gli1 antibody [HL247] (GTX635619)

RecombinantKOKD-ValidationProtein Overexpression

 

References

  1. Nat Methods. 2016 Oct;13(10):823-7.
  2. “Supplier antibody validation: how much progress has been made?” (blog.citeab.com/supplier-antibody-validation-progress/)