Fab-ZAP human [IT-51, KIT-51]

a tool to “piggyback” onto YOUR antibody via goat anti-human monovalent antibody; targeting cells that recognize YOUR human antibody, eliminated via saporin

SKU: IT-51 Category: Quantity: Individual 25 ug, Individual 100 ug, Individual 250 ug, Individual 1 mg, Kit w/controls 25 ug, Kit w/controls 100 ug, Kit w/controls 250 ug, Kit (1 ab) w/controls & developing reagents, tests 1 ab, Kit (4 ab) w/controls & developing reagents, tests 4 abs, Kit (10 ab) w/controls & developing reagents, tests 10 abs | Antibody Type: affinity-purified | Host: goat | Reactivity: human | Conjugate: saporin | Usage: eliminates cells, screen antibodies |

Fab-ZAP uses your primary human IgG antibody to target and eliminate cells that recognize your primary antibody. Fab-ZAP is made with a monovalent secondary antibody eliminating the possibility of cap formation, while preserving all the qualities that make an effective in vitro diagnostic tool. The antibodies used are affinity-purified polyclonal antibodies against both the heavy and light chain of human IgG. The antibody used in this product will cross-react across immunoglobulin classes and subclasses of the same species as they share the same light chain (either kappa or lambda). It also has an improved EC50 when directly compared to Hum-ZAP in a cytotoxicity assay.

Fab-ZAP human is a chemical conjugate of goat anti-human monovalent antibody and the ribosome-inactivating protein, saporin. It uses your human primary antibody to target and eliminate cells. This secondary conjugate is used to evaluate the potential of a primary antibody to internalize.

SK-BR-3 cells were plated at 1000 cells/90 μl/well and incubated overnight. Trastuzumab and Saporin dilutions were made in cell media and 10 μl was added to each well.  The Trastuzumab was also diluted in cell media containing, at a final concentration, 4.5 nM/10 μl Fab-ZAP, and 10 μl was added to each well. The plates were incubated for 72 hours. The plates were developed using a solution of XTT/PMS and read at 450 nm. Cytotoxicity was analyzed by comparing well readings of the treated wells to those of the control wells, expressed as a percentage. The number of viable cells remaining on the day of development is measured via cell metabolism of a colorimetric molecule within the developing reagents. Analysis was performed using Prism software (GraphPad, San Diego).

Fab-ZAP human is available individually (Cat. #IT-51) or as a kit (Cat. #KIT-51) which includes Fab-ZAP humanSaporin (Cat. #PR-01)Fab IgG-SAP (Cat. #IT-67) and reagents for developing a cytotoxicity assay.

Other ZAP Conjugates:

Need another ZAP Conjugate for your target? Check here for other species & targets including in vivo and in vitro options.

keywords: antibody, efficacy, immunotoxin, screening, internalization, saporin, Fab-ZAP, monovalent antibody, secondary conjugate, primary antibody, goat anti-human monovalent antibody


  1. Verified User

    I have tried your Fab-Zap assay here recently and your protocols are spot on. It worked great.

  2. Verified User

    I had the pleasure of ordering the FAB-ZAP human and mouse kit from your company a few months ago. The results achieved with this kit have been truly outstanding and I appreciate the quality of your products.

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View Data Sheet

Mab-ZAP: A tool for evaluating antibody efficacy for use in an immunotoxin.

Kohls MD, Lappi DA (2000) Mab-ZAP: A tool for evaluating antibody efficacy for use in an immunotoxin. BioTechniques 28(1):162-165. doi: 10.2144/00281pf01

Summary: Immunotoxins are useful tools for elimination of specific cell populations in vitro and in vivo for research and therapeutic applications. One of the factors limiting the use of immunotoxins is the selection of an appropriate antibody. Advanced Targeting Systems has created a reagent that allows researchers to select antibodies with the desired characteristics before an immuntoxin is made, purified, and assayed. Using a goat anti-murine IgG coupled to the ribosome-inactivating protein saporin, researchers can screen hundreds of antibodies in a time and cost-effective manner.

Related Products: Mab-ZAP (Cat. #IT-04), Rab-ZAP (Cat. #IT-05), Hum-ZAP (Cat. #IT-22), Rat-ZAP (Cat. #IT-26), Anti-M-ZAP (Cat. #IT-30), Goat-ZAP (Cat. #IT-36)

Streptavidin-saporin: Converting biotinylated materials into targeted toxins

Ancheta LR, Shramm PA, Bouajram R, Higgins D, Lappi DA (2023) Streptavidin-saporin: Converting biotinylated materials into targeted toxins. Toxins 15(3):181. doi: 10.3390/toxins15030181

Summary: This manuscript describes the myriad of ways Streptavidin-ZAP is used and how this technology supports the scientific process of ‘Molecular Surgery’ and progress in research and drug development. Insights from publications and research performed using Streptavidin-ZAP and its impact on academia and industry for research and drug development are presented.

Read the full article.

Related Products: Streptavidin-ZAP (Cat. #IT-27)

Evaluate Potential Targeting Molecules.

Kohls M (2006) Evaluate Potential Targeting Molecules. Nature Methods

Summary: Targeted toxins -- targeting agents conjugated to saporin -- are widely used to eliminate specific cell populations both in vitro and in vivo. For these molecules to be effective, it is vital that the targeting component of the conjugate specifically binds the cells of interest. A secondary conjugate, Streptavidin-ZAP, has been created by attaching the toxin saporin to streptavidin. The user can combine primary biotinylated material with Streptavidin-ZAP to quickly and economically screen potential targeting molecules for internalization and specificity. Once the appropriate targeting molecule is identified, a direct conjugation with saporin can be performed.

Related Products: Streptavidin-ZAP (Cat. #IT-27)

Read the article.

Saporin as a commercial reagent: its uses and unexpected impacts in the biological sciences-tools from the plant kingdom

Ancheta LR, Shramm PA, Bouajram R, Higgins D, Lappi DA (2022) Saporin as a commercial reagent: its uses and unexpected impacts in the biological sciences-tools from the plant kingdom. Toxins (Basel) 14(3):184. doi: 10.3390/toxins14030184

Read complete article.


Saporin is a ribosome-inactivating protein that can cause inhibition of protein synthesis and causes cell death when delivered inside a cell. Development of commercial Saporin results in a technology termed ‘molecular surgery’, with Saporin as the scalpel. Its low toxicity (it has no efficient method of cell entry) and sturdy structure make Saporin a safe and simple molecule for many purposes. The most popular applications use experimental molecules that deliver Saporin via an add-on targeting molecule. These add-ons come in several forms: peptides, protein ligands, antibodies, even DNA fragments that mimic cell-binding ligands. Cells that do not express the targeted cell surface marker will not be affected. This review will highlight some newer efforts and discuss significant and unexpected impacts on science that molecular surgery has yielded over the last almost four decades. There are remarkable changes in fields such as the Neurosciences with models for Alzheimer’s Disease and epilepsy, and game-changing effects in the study of pain and itch. Many other uses are also discussed to record the wide-reaching impact of Saporin in research and drug development.

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Fab IgG-SAP (Cat. #IT-67)

Fab-ZAP human (Cat. #IT-51)

Fab-ZAP mouse (Cat. #IT-48)

Fab-ZAP rabbit (Cat. #IT-57)

Fab-ZAP rat (Cat. #IT-55)

Fab-pHast human (Cat. #PH-01)

Saporin (Cat. #PR-01)

Hum-ZAP (Cat. #IT-22)

FabFc-ZAP human (Cat. #IT-65)

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Targeting Tools: Fab-ZAPs

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Choosing the Correct Secondary Conjugate

Detecting the targeted antibody in supernatant

Targeting B Cells

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ZAP Antibody Internalization Kit Introduction

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ZAP Antibody Internalization Kit literature

Cytotoxicity Assay Protocol for ZAP Antibody Internalization Kits

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Concentration Calculations: Convert molarity to mg/ml and mg/ml to molarity (PDF worksheet)

Preparing and Interpreting Cytotoxicity Data in vitro

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