Our functional antibodies elucidate or affect the cellular functions of interest. These antibodies are quality-tested in-house for in vitro and in vivo functional assays such as blocking, neutralization, or activation. They are available in Low Endotoxin, Azide-Free (LEAF™) and Ultra-Low Endotoxin, Azide-Free (Ultra-LEAF™) formulations. Both are 0.2 µm filtered and eliminate unwanted effects from endotoxin and sodium azide (Table 1).


Among our selection of functional antibodies, GoInVivo™ products specialize in targeting immune checkpoint receptors, an important step in soluble factor-based immunotherapy to boost a patient’s own anti-tumor activity to fight cancer cells. GoInVivo™ products are all validated by a functional assay, formulated free of sodium azide, guaranteed pathogen-free based on PCR testing, and offered in bulk quantities (Table 1) at an exceptional price.


LEAF™, Ultra-LEAF™

  • Quality-tested by functional assays for selected targets
  • Formulated free of sodium azide
  • 0.2 µm filtered to reduce endotoxin



View LEAF™ and Ultra-LEAF™ antibodies


  • Specialized to target immune checkpoint receptors
  • Validated by functional assay
  • Formulated free of sodium azide
  • Guaranteed pathogen-free based on PCR testing
  • Offered in bulk quantities

View GoInVivo™ antibodies

Table 1.





Quality Tested by Flow Cytometry

Free of Preservatives

Custom Bulk Sizing

Off-the-shelf Sizes

5 mg – 1 g

100 µg – 100 mg

50 µg, 500 µg

Endotoxin Levels

< 1 EU/mg

< 10 EU/mg

< 100 EU/mg

Functionally Validated*



Pathogen Tested**




* All GoInVivo™ antibodies are validated with in vitro functional assays, and in some cases, in vivo applications. Our Ultra-LEAF™ antibodies are functionally tested for selected targets only.

** All GoInVivo™ antibodies are pathogen free as tested by qPCR for up to 20 pathogens, including Mycoplasma.

Bulk Advantages

For some experiments, like animal models receiving in vivo antibody treatements, large quantities of antibodies can be required. To help researchers with these needs, we provide the ability to buy in large batches, which includes several benefits, including:

  • Outstanding value
  • Each lot is quality-tested and backed by our 100% guarantee
  • Bulk orders provided in the Ultra-LEAF™ format (<0.01 EU/µg of protein)
  • Rapid turnaround time

We also provide custom options for your functional antibodies: 

  • Bulk production from your hybridoma
  • Custom concentrations available
  • Custom endotoxin limits
  • Custom formulation of purified or fluorophore-conjugated antibody
  • Flexible packaging

Understand the Immune System With Functional Antibodies - B Cell Focus


While our library of functional antibodies can investigate the characteristics of a variety of cells, we wanted to specifically focus on how we are accelerating your research on B cells. In particular, our novel functional anti-mouse CD20 antibodies are ideal for investigating B cells in mediating immune responses and autoimmune disorders. These antibodies serve as a tool to study properties of B cell depletion on tissues, eliminating the need to use genetically modified mice when B cell-deficient animals are needed. 

Ultra-LEAF™ Purified anti-mouse CD20 Recombinant Antibody (clone QA18A73)


Our anti-mouse CD20 recombinant antibody (clone QA18A73) was designed with a mouse isotype for increased in vivo stability and delayed clearance. It shows more sustained B cell depletion over our previous clone, SA271G2.


C57BL/6 mice were retro-orbitally injected with 200 µg of Ultra-LEAF™ purified anti-mouse CD20 (clone SA271G2, black line, N=4), Ultra-LEAF™ purified anti-mouse CD20 recombinant (clone QA18A73, purple line, N=4), or vehicle only (PBS, red line, N=4). Peripheral blood was analyzed at indicated intervals, and average % B cells calculated for each group (measured as % CD19+B220+ cells).

Ultra-LEAF™ Purified anti-mouse CD20 Antibody (clone SA271G2)


Our validation studies show how effectively in vivo administration of monoclonal anti-mouse antibody (clone SA271G2) depletes only the immature B cell subset from bone marrow, but not pre-pro, pro, or pre-B cells.


In vivo administration of mAb SA271G2 depletes immature stage of bone marrow B cells. Bone marrow cells from SA271G2-treated mice or the isotype-treated control group were stained to identify the different B cell subsets. Only the immature B cells (CD19hi/B220hi) were depleted. Data shown was gated on the lymphoid population.

Likewise, treatment with mAb SA271G2 only depletes the CD20+ cells, without any effect on T cells, macrophages, or other cell types. Moreover, tissue integrity of the spleen was maintained despite the almost complete absence of B cells.


C57BL/6 mice were injected intravenously with 250 μg of Ultra-LEAF™ Purified anti-mouse CD20 (clone SA271G2) (right) or Ultra-LEAF™ Purified rat IgG2b, isotype control (left). At day 7, the spleens were collected, sectioned, and stained for CD19 (red), CD3 (cyan), CD169 (green), CD11b (yellow), and F4/80 (blue) in microscopy analysis.


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