iF700 Anti-Human CD22 Antibody

Product Details


CloneHIB22
ApplicationFlow Cytometry
ReactivityHuman
FormatiF700
Target NameCD22, BL-CAM, Siglec-2
IsotypeMouse IgG1
Antibody TypeMonoclonal
Regulatory StatusRUO
FormulationPhosphate-buffered solution, pH 7.2, containing 0.09% sodium azide and 0.2% (w/v) BSA
Protein ConcentrationSupplied at a lot-specific concentration.
Storage&HandlingThe antibody solution should be stored undiluted between 2°C and 8°C, and protected from prolonged exposure to light. Do not freeze.
Recommended UsageFor flow cytometric staining, it is recommended to use 5 uL of this reagent per 0.5-1.0 million cells in a 100 µL volume. Optimal reagent performance should be determined by titration for each specific application. iF700 has an excitation max at 690 nm and an emission max at 710 nm.
Excitation LaserRed Laser (633 nm)
Research AreasB cells, Cancer Marker
See All FormatsClone HIB22

Background Information


CD22 is a B cell–specific transmembrane glycoprotein that functions as an important regulator of B cell receptor (BCR) signaling and immune tolerance. Also known as Siglec-2, CD22 belongs to the sialic acid–binding immunoglobulin-like lectin (Siglec) family and is expressed almost exclusively on mature B cells, with expression increasing as B cells progress from the naïve to mature stages. Through its inhibitory signaling capacity, CD22 helps fine-tune B cell activation and prevent inappropriate immune responses.

Structurally, CD22 is a type I transmembrane protein with a large extracellular region composed of seven immunoglobulin-like domains. The N-terminal domain mediates binding to sialic acid–containing glycans, which serve as its primary ligands. CD22 preferentially recognizes α2,6-linked sialic acids that are commonly present on glycoproteins and glycolipids expressed on B cells themselves (cis interactions) as well as on neighboring cells (trans interactions). The cytoplasmic tail of CD22 contains multiple immunoreceptor tyrosine-based inhibitory motifs (ITIMs), which are essential for its signaling function. Functionally, CD22 acts as a negative regulator of BCR signaling. Upon BCR engagement, CD22 becomes phosphorylated and recruits phosphatases such as SHP-1 to its ITIM motifs. These phosphatases attenuate downstream signaling pathways, thereby raising the threshold for B cell activation. Through this mechanism, CD22 contributes to the maintenance of B cell tolerance and limits excessive antibody production. CD22 also influences B cell survival, migration, and interactions within lymphoid tissues.

Dysregulation of CD22 expression or signaling has been linked to immune-mediated diseases and malignancy. Reduced CD22 function can lead to hyperactive B cells and has been associated with autoimmune diseases such as systemic lupus erythematosus. In contrast, CD22 is frequently overexpressed on B cell malignancies, including B cell acute lymphoblastic leukemia (B-ALL) and certain non-Hodgkin lymphomas, making it an attractive diagnostic and therapeutic target.

CD22 plays a significant role in therapeutics, particularly in the treatment of B cell cancers. Antibody-based therapies targeting CD22 have been developed to selectively eliminate malignant B cells. Notably, antibody–drug conjugates and immunotoxins that bind CD22 deliver cytotoxic agents directly to cancerous B cells, sparing most non–B cell populations. CD22 is also being explored as a target for engineered cell therapies and for strategies aimed at modulating B cell activity in autoimmune disease. Together, these approaches highlight CD22 as a key molecule at the intersection of B cell biology, disease, and targeted therapy.

Isotype Control


iF700 Mouse IgG1 Isotype Control Antibody

Data Sheets


iF700 Anti-Human CD22 Antibody TDS

Related Protocols


Flow Cytometry Protocol

Frequently Asked Questions


How do I determine the optimal antibody concentration/titer for my experiment?
We recommend titrating each new antibody lot on your own cell type and instrument, since optimal concentration depends on cell density, target expression level, and cytometer sensitivity. Suggested starting dilutions or test sizes (e.g., µg or µl per 10^6 cells) are provided on the product page as a starting reference point, not a fixed requirement.

Can these antibodies be used for intracellular or intranuclear staining, or only surface staining?
Intended use (surface, intracellular, or both) is specified per product, indicated under Application. The appropriate Related Protocol is linked for each product. If you need to detect both surface and intracellular markers in the same panel, confirm each antibody's compatibility with your fixation/permeabilization protocol before combining them.

What controls should I use alongside these antibodies?
Matched isotype controls (same host species, isotype, and conjugate) are available for most clones to help distinguish specific binding from background/non-specific staining and are linked on each product page. Unstained, single-color compensation, and fluorescence-minus-one (FMO) controls are also recommended, especially for multicolor panel design.

Can I combine InnoCyto Flow Cytometry antibodies into a multicolor panel?
Yes — antibodies across our catalog are designed to be panel-compatible, and conjugate options are offered specifically to support multiplexing. When building a panel, pair bright fluorophores with low-expression targets, avoid excessive spectral overlap, and confirm compensation is set up correctly for your specific fluorochrome combination. Use our Panel Builder to simplify the process.

Have a product or application question? Consult our FAQs or contact us.