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Single-cell analysis

Flow Cytometry Antibodies for Cell Identification and Functional Analysis

Flow cytometry antibodies recognize surface or intracellular markers on individual cells and are commonly supplied with fluorescent labels for direct detection. Researchers use them to identify cell populations, measure marker expression, investigate signaling events and evaluate cellular responses within complex samples. Compare available antibodies by target, clone, species reactivity, fluorophore, isotype, staining location, validated protocol, panel compatibility and pack size.

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Browse Flow Cytometry Antibodies

Compare product names, catalog numbers, available sizes, pricing, and product specifications.

How do flow cytometry antibodies work?

Flow cytometry antibodies bind specific antigens expressed on the surface of cells or within fixed and permeabilized cells. Fluorescent labels attached to these antibodies emit detectable signals when excited by the instrument's lasers, allowing cells to be measured individually as they pass through the flow cell. The resulting fluorescence intensity can help distinguish cell populations and estimate relative marker expression.

Researchers use flow cytometry antibodies for immunophenotyping, cell counting, viability analysis, intracellular cytokine detection, phosphorylation studies, cell-cycle analysis and functional assays. Multiple markers can be measured in the same sample by combining antibodies carrying spectrally distinct fluorophores. The number of simultaneous measurements depends on the cytometer configuration, panel design, reagent compatibility and sample quality.

Reliable results require more than selecting an antibody against the correct target. Clone behavior, fluorophore brightness, antigen abundance, sample processing, nonspecific Fc receptor binding and spectral overlap can all influence population separation. Controls, compensation or spectral unmixing and a predefined gating strategy are necessary for distinguishing biological signal from autofluorescence, spillover and background staining.

Buying and selection guide

How to choose flow cytometry antibodies

Start with the biological populations and measurements required by the experiment, then design the antibody panel around antigen abundance, instrument configuration and sample characteristics.

01

Confirm target and clone

Verify that the selected clone recognizes the intended species and antigen form and has been validated for flow cytometry under relevant staining conditions.

02

Match fluorophores to the instrument

Choose fluorophores that can be excited by the available lasers and detected through the cytometer's installed optical filters.

03

Consider antigen abundance

Assign brighter fluorophores to weakly expressed markers and less intense fluorophores to abundant markers to improve population resolution.

04

Control spectral overlap

Review fluorophore emission overlap and plan appropriate compensation or spectral unmixing controls for every labeled reagent in the panel.

05

Check staining location

Determine whether the antigen is expressed on the cell surface or intracellularly because fixation and permeabilization can alter antigen recognition and fluorophore performance.

06

Plan biological and technical controls

Include unstained, single-stained, viability, fluorescence-minus-one and relevant biological controls based on the panel and experimental question.

Frequently asked questions about flow cytometry antibodies

These questions cover antibody selection, fluorophore assignment, panel controls, staining optimization and common causes of poor population separation.

What makes an antibody suitable for flow cytometry?

An antibody suitable for flow cytometry should recognize its target on cells processed under the intended staining conditions. The exact product should be validated for flow cytometry, and its clone, species reactivity, fluorophore and antigen location should match the experiment. An antibody that works in Western blotting or immunohistochemistry may not recognize the native cellular antigen.

How do I choose a fluorophore for a flow cytometry antibody?

Choose a fluorophore that matches the cytometer's lasers and detection filters while fitting the complete panel. Bright fluorophores are generally assigned to low-abundance targets, whereas highly expressed markers can use dimmer labels. Spectral overlap, tandem-dye stability, cellular autofluorescence and the importance of each marker should also be considered.

What is the difference between compensation and fluorescence-minus-one controls?

Compensation controls measure how fluorescence from one label spreads into other detector channels and are used to correct spectral spillover. Fluorescence-minus-one controls contain every antibody except one and help define the boundary between negative and positive populations for that marker. They address different problems and may both be needed in a multicolor experiment.

Why are my positive and negative populations not clearly separated?

Poor separation may result from weak antigen expression, an unsuitable fluorophore, excessive background, incorrect antibody concentration, dead cells, autofluorescence or suboptimal instrument settings. The selected clone may also have limited affinity under the staining conditions. Titrating the antibody and reviewing sample quality, controls and panel design can help identify the cause.

Do I need to titrate every flow cytometry antibody?

Titration is strongly recommended because the optimal concentration depends on the clone, fluorophore, cell type, antigen abundance, staining volume and sample preparation. Using too much antibody can increase background and spreading error, while too little can reduce sensitivity. The concentration printed on a datasheet is a starting point rather than a universal optimum.

Can I use the same antibody for surface and intracellular staining?

Only when the antibody is validated under both conditions. Fixation and permeabilization can change epitope structure, reduce fluorescence or increase nonspecific binding. Surface markers may also be lost or internalized during processing. Review the product documentation and test the antibody with the exact fixation and permeabilization method planned for the experiment.

Which controls should I include in a multicolor flow cytometry panel?

A typical panel may require unstained cells, single-stained controls, viability controls, fluorescence-minus-one controls and appropriate biological positive and negative samples. Isotype controls can help investigate certain forms of nonspecific binding but do not replace fluorescence-minus-one or biological controls. Compensation beads may be useful when positive cells are unavailable.

Why is an isotype control not enough to set every flow cytometry gate?

An isotype control can estimate background caused by nonspecific interactions from an antibody of a matching class, but it does not reproduce fluorescence spillover, marker-specific biology or differences in antibody binding. Gates are usually more reliable when informed by biological controls, fluorescence-minus-one controls, unstained samples and knowledge of the expected cell populations.

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