Antibody Labeling Kits
Any antibody. Any color. Any time.
FlexAble is a novel antibody labeling kit that uses an affinity linker to conjugate fluorochromes, enzymes, and molecules in any buffer condition. Suitable for single or multiplex staining.

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1
Compatible with primary antibodies from any supplier
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4
Label as little as 0.5ug. No buffer exchange needed.
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Works with any antibody concentration and formulation
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Enable same species multiplexing
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Fast and easy 2-step protocol – Ready to use in 10 minutes
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No additional equipment required

FlexAble is a novel antibody labeling kit that uses an affinity linker to conjugate fluorochromes, enzymes, and molecules in any buffer condition. Suitable for single or multiplex staining.

-
1
Compatible with primary antibodies from any supplier
-
2
Works with any antibody concentration and formulation
-
3
Fast and easy 2-step protocol – Ready to use in 10 minutes
-
4
Label as little as 0.5ug. No buffer exchange needed.
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5
Label up to 50 different antibodies with 1 kit
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6
No additional equipment required

Immunofluorescence of human kidney: FFPE human kidney sections were stained with anti-Calbindin antibody (14479-1-AP) labeled with FlexAble CoraLite® Plus 555 Kit (KFA002, yellow), anti-ACE2 antibody (66699-1-Ig) labeled with FlexAble CoraLite® Plus 647 Kit (KFA023, magenta), CoraLite®488-conjugated Podocalyxin antibody (CL488-18150, green), and DAPI (blue).

Immunofluorescence of rat brain tissue: FFPE rat brain tissue sections were stained with anti-MAP2 antibody (17490-1-AP) labeled with FlexAble CoraLite® Plus 555 Kit (KFA002, orange), anti-GFAP antibody (16825-1-AP) labeled with FlexAble CoraLite® Plus 647 Kit (KFA003, magenta), and CoraLite®488-conjugated TDP-43 antibody (CL488-10782, green).

Immunofluorescence of rat brain tissue: FFPE rat brain tissue sections were stained with anti-NeuN antibody (66836-1-Ig) labeled with FlexAble CoraLite® Plus 647 Kit (KFA023, magenta), anti-TUBB3 antibody (66375-1-Ig) labeled with FlexAble CoraLite® Plus 555 Kit (KFA022, orange), and CoraLite®488-conjugated GFAP antibody (CL488-60190, green).

Immunofluorescence of HeLa: PFA-fixed HeLa cells were stained with anti-TDP43 antibody (10782-2-AP) labeled with FlexAble CoraLite® 488 Kit (KFA001, green), anti-Tom20 antibody (11802-1-AP) labeled with FlexAble CoraLite® Plus 555 Kit (KFA002, red), and anti-Lamin B1 antibody (12987-1-AP) labeled with FlexAble CoraLite® Plus 647 Kit (KFA003, cyan). Confocal images were acquired with a 100x oil objective and post-processed. Images were recorded at the Core Facility Bioimaging at the Biomedical Center, LMU Munich.

Immunofluorescence of HeLa: PFA-fixed HeLa cells were stained with anti-Lamin B1 antibody (66095-1-Ig) labeled with FlexAble CoraLite® 488 Kit (KFA021, green), anti-HSP60 (66041-1-Ig) labeled with FlexAble CoraLite® Plus 555 Kit (KFA022, red), and anti-GORASP2 antibody (66627-1-Ig) labeled with FlexAble CoraLite® Plus 647 Kit (KFA023, cyan). Confocal images were acquired with a 100x oil objective and post-processed. Images were recorded at the Core Facility Bioimaging at the Biomedical Center, LMU Munich.

Immunofluorescence of HeLa: PFA-fixed HeLa cells were stained with anti-HSP60 antibody (66041-1-Ig) labeled with FlexAble CoraLite® Plus 555 Kit (KFA022, yellow), anti-GORASP2 antibody (66627-1-Ig) labeled with FlexAble CoraLite® Plus 647 Kit (KFA023, cyan), and DAPI (blue). Confocal images were acquired with a 100x oil objective and post-processed. Images were recorded at the Core Facility Bioimaging at the Biomedical Center, LMU Munich.

Immunofluorescence of HeLa: PFA-fixed HeLa cells were stained with anti-COXIV antibody (11242-1-AP) labeled with FlexAble CoraLite® Plus 555 Kit (KFA002, yellow), anti-GM130 antibody (11308-1-AP) labeled with FlexAble CoraLite® Plus 647 Kit (KFA003, magenta), and DAPI (blue). Confocal images were acquired with a 100x oil objective and post-processed. Images were recorded at the Core Facility Bioimaging at the Biomedical Center, LMU Munich.

Immunofluorescence of HeLa: PFA-fixed HeLa cells were stained with anti-TOM20 antibody (11802-1-AP) labeled with FlexAble CoraLite® Plus 555 Kit (KFA002, yellow) and anti-Lamin B1 antibody (12987-1-AP) labeled with FlexAble CoraLite® Plus 647 Kit (KFA003, cyan). Confocal images were acquired with a 100x oil objective and post-processed. Images were recorded at the Core Facility Bioimaging at the Biomedical Center, LMU Munich.

Flow cytometry of PBMC. 1X10^6 human peripheral blood mononuclear cells (PBMCs) were stained with 0.5 µg anti-human CD45 antibody (clone HI30, 65109-1-Ig) labeled with FlexAble CoraLite® Plus 405 Kit (KFA026).

Flow cytometry of PBMC. 1X10^6 human peripheral blood mononuclear cells (PBMCs) were stained with 0.5 µg anti-HSP90 antibody (13171-1-AP) labeled with FlexAble CoraLite® 488 Kit (KFA001, cyan) or with isotype control antibody labeled with FlexAble CoraLite® 488 Kit (KFA001, red).

Flow cytometry of PBMC. 1X10^6 human peripheral blood mononuclear cells (PBMCs) were stained with 0.5 µg anti-human CD3 antibody (clone UCHT1, 65151-1-Ig) labeled with FlexAble CoraLite® 488 Kit (KFA021).

Flow cytometry of Jurkat cells. 1X10^6 Jurkat cells were stained with 0.5 µg anti-HSP90 antibody (13171-1-AP) labeled with FlexAble CoraLite® Plus 555 Kit (KFA002, cyan) or with isotype control antibody labeled with FlexAble CoraLite® Plus 555 Kit (KFA002, red).

WB of HeLa cell lysates: HeLa cell lysates were detected with anti-GAPDH antibody (10494-1-AP) labeled with FlexAble CoraLite® Plus 555 Kit (KFA002, green) and anti-NUDT21 antibody (66335-1-Ig) labeled with FlexAble CoraLite® Plus 647 Kit (KFA023, red).

WB of HEK293 cell lysates: siRNA transfected HEK293 cell lysates were detected with anti-GNA13 antibody (67188-1-Ig) labeled with FlexAble CoraLite® Plus 555 Kit (KFA022,green) and anti-PCNA antibody (60097-1-Ig) labeled with FlexAble CoraLite® Plus 647 Kit (KFA023, red).

WB of A431 cell lysates: siRNA transfected A431 cell lysates were detected with anti-P53 antibody (80077-1-RR) labeled with FlexAble CoraLite® Plus 555 Kit (KFA002, green) and anti-GAPDH antibody (10494-1-AP) labeled with FlexAble CoraLite® Plus 647 Kit (KFA003, red).

WB of HeLa cell lysates: HeLa cell lysates were detected with anti-GAPDH antibody (10494-1-AP) labeled with FlexAble CoraLite® Plus 647 Kit (KFA003, red) and anti-NUDT21 antibody (66335-1-Ig) labeled with FlexAble CoraLite® Plus 555 Kit (KFA022, green).

WB of HEK293 cell lysates: HEK293 cell lysates were detected with anti-GAPDH antibody (10494-1-AP) labeled with FlexAble CoraLite® 488 Kit (KFA001, green) and anti-NUDT21 antibody (66335-1-Ig) labeled with FlexAble CoraLite® Plus 750 Kit (KFA024, red).

WB of HEK293 cell lysates: HEK293 cell lysates were detected with anti-GAPDH antibody (10494-1-AP) labeled with FlexAble CoraLite® Plus 750 Kit (KFA004, red) and anti-NUDT21 antibody (66335-1-Ig) labeled with FlexAble CoraLite® 488 Kit (KFA021, green).

WB of A431 cell lysates: siRNA transfected A431 cell lysates were detected with anti-P53 antibody (80077-1-RR) labeled with FlexAble CoraLite® Plus 555 Kit (KFA002, green) and anti-PCNA antibody (60097-1-Ig) labeled with FlexAble CoraLite® Plus 647 Kit (KFA023, red).

WB of HepG2 cell lysates: siRNA transfected HepG2 cell lysates were detected with anti-CCDC111 antibody (29824-1-AP) labeled with FlexAble CoraLite® Plus 647 Kit (KFA003, red) and anti-PCNA antibody (60097-1-Ig) labeled with FlexAble CoraLite® Plus 555 Kit (KFA022, green).
Antibody labeling with FlexAble is achieved by using a high-affinity, non-covalent FlexLinker. The FlexLinker binds tightly to the antibody within minutes and once bound does not release from the antibody. Unbound FlexLinker is neutralized by adding a FlexQuencher.
The labeling reaction using FlexAble yields a homogenous, well-defined antibody that is fully functional. Neither aggregation nor a loss of antibody is observed during the labeling.

FlexAble labeling kits can be used to label:
- Primary antibodies from any supplier
- Antibodies of any concentration
- Antibodies in any buffer formulation
FlexAble Antibody Labeling Kits have been thoroughly validated with primary antibodies from different suppliers. Primary antibodies with low concentration, antibodies stored in 50% glycerol, and antibodies supplemented with carriers like BSA are compatible for use with the FlexAble kits.
The FlexAble Antibody Labeling Kit works with any antibody formulation. Labeling with the high-affinity FlexLinker is not affected by stabilizers like BSA or glycerol, amine-containing buffers, or preservatives.
Antibody buffer formulation
FlexAble Antibody Labeling Kits work with any antibody formulation without the need to purify or buffer-exchange prior to labeling. This saves time and money and also avoids the loss of antibody that can happen during those processes. Since FlexAble utilizes a high-affinity FlexLinker molecule that binds site-specifically to an antibody, the binding reaction is not affected by carriers like BSA or glycerol, amine-containing buffers like Tris, or preservatives like sodium azide.

Anti-CD3 antibody, previously stored in the indicated concentration of glycerol, was efficiently labeled with FlexAble Antibody Labeling Kit regardless of the glycerol concentration during labeling. 1X10^6 human peripheral blood mononuclear cells (PBMCs) were stained with 0.5 µg anti-human CD3 antibody (clone UCHT1, 65151-1-Ig) labeled with FlexAble CoraLite® Plus 647 Kit (KFA023) . Cells were gated for live singlet lymphocytes.
Antibody Concentration
A highly concentrated antibody can be used without pre-dilution, or an antibody of low concentration can be used without further concentrating it. FlexAble is especially suitable for low-concentration antibodies due to the high affinity of the FlexLinker. Antibody concentrations as low as 0.06 mg/mL have been efficiently labeled with FlexAble.
Labeling antibodies with FlexAble is fast and easy due to a simple 2-step protocol. The procedure only requires about 30 seconds of hands-on time and only a pipette is needed. Mix your primary antibody, FlexLinker, and FlexBuffer together and incubate for 5 minutes. Add FlexQuencher to neutralize unbound FlexLinker and incubate again for 5 minutes. The antibody is ready for use in the time it takes to label your tubes.

FlexAble Antibody Labeling Kits simplify multiplexing in immunofluorescence, western blotting, and flow cytometry. Save hands-on and incubation time by completing labeling of all your antibodies in 10 minutes before your experiment, followed by multiplex staining with all labeled antibodies at the same time. If primary antibodies of different species are used, they can even be labeled simultaneously in the same tube with FlexAble.

Antibodies labeled with FlexAble Antibody Labeling Kits can be used alone or in multiplex experiments with:
- Other antibodies labeled with FlexAble Antibody Labeling Kits
- Commercially available pre-conjugated primary antibodies
- Other primary and secondary antibody combinations

Immunofluorescence of rat brain tissue: FFPE rat brain tissue sections were stained with anti-NeuN antibody (66836-1-Ig) labeled with FlexAble CoraLite® Plus 647 Kit (KFA023, magenta), anti-TUBB3 antibody 66375-1-Ig) labeled with FlexAble CoraLite® Plus 555 Kit (KFA022, orange), and CoraLite®488-conjugated GFAP antibody (CL488-60190, green).
FlexAble enables same species multiplexing
Same species multiplexing usually requires complex protocols that include primaries from different species/isotypes combined with highly specific and cross-adsorbed secondary antibodies. An alternative is pre-conjugated antibodies; however, not every antibody may be available in a pre-conjugated version.

FlexAble provides the easiest way to multiplex antibodies from the same species and isotype. FlexLinker binds to the primary antibody with high affinity and specificity and does not release from the antibody once bound. Therefore, antibodies from the same species or isotype can be incubated with the sample at the same time after being labeled with FlexAble. No leaking or cross-binding to other antibody isotypes has been observed.
![immunofluorescence staining of HeLa cells with TDP43 antibody,] and Lamin B1 antibody](https://www.ptglab.com/media/mqqpqn0g/1-immunofluorescence-of-hela-with-anti-tdp-43-antibody-anti-tom20-and-anti-lamin-b1-antibody.jpg)
Immunofluorescence of HeLa: PFA-fixed HeLa cells were stained with anti-TDP43 antibody (10782-2-AP) labeled with FlexAble CoraLite® 488 Kit (KFA001, green), anti-Tom20 antibody (11802-1-AP) labeled with FlexAble CoraLite® Plus 555 Kit (KFA002, red), and anti-Lamin B1 antibody (12987-1-AP) labeled with FlexAble CoraLite® Plus 647 Kit (KFA003, cyan). Confocal images were acquired with a 100x oil objective and post-processed. Images were recorded at the Core Facility Bioimaging at the Biomedical Center, LMU Munich.

CoraLite Plus spectra
CoraLite® and CoraLite® Plus dyes are bright fluorescent dyes from Proteintech that deliver high photostability and minimal fluorescent bleed through, making it easy to combine two or more dyes in an experiment. Our FlexAble Kits are conjugated to multiple CoraLite® and CoraLite® Plus dyes to offer more flexibility in multiple labeling experiments.
CoraLite® and CoraLite® Plus dyes have equivalent brightness to the Alexa Fluor® dyes. Each fluorophore can be used simultaneously in co-localization studies due to the minimum overlapping fluorescence spectra. The CoraLite line of FlexAble enables faster and simpler multiplex detection by immunofluorescence, western blotting and flow cytometry.
FlexAble Antibody Labeling Kits
CoraLite® and CoraLite® Plus dyes have equivalent brightness to the Alexa Fluor® dyes.
Conjugate | Size | Compatible with |
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CoraLite® Plus 405 | 10 rxn, 50 rxn, 200 rxn | Rabbit IgG, Mouse IgG1, Mouse IgG2a, Mouse IgG2b NEW |
FITC Plus | 10 rxn, 50 rxn, 200 rxn | Rabbit IgG, Mouse IgG1, Mouse IgG2a, Mouse IgG2b NEW |
CoraLite® Plus 488 | 10 rxn, 50 rxn, 200 rxn | Rabbit IgG, Mouse IgG1, Mouse IgG2a, Mouse IgG2b |
CoraLite® Plus 555 | 10 rxn, 50 rxn, 200 rxn | Rabbit IgG, Mouse IgG1, Mouse IgG2a, Mouse IgG2b |
CoraLite® Plus 647 | 10 rxn, 50 rxn, 200 rxn | Rabbit IgG, Mouse IgG1, Mouse IgG2a, Mouse IgG2b |
CoraLite® Plus 750 | 10 rxn, 50 rxn, 200 rxn | Rabbit IgG, Mouse IgG1, Mouse IgG2a, Mouse IgG2b NEW |
Horseradish Peroxidase (HRP) NEW | 10 rxn, 50 rxn, 200 rxn | Rabbit IgG, Mouse IgG1, Mouse IgG2a, Mouse IgG2b |
Biotin NEW | 10 rxn, 50 rxn, 200 rxn | Rabbit IgG, Mouse IgG1, Mouse IgG2a, Mouse IgG2b |
Alexa Fluor® is a registered trademark of Molecular Probes, Inc, a Thermo Fisher Scientific Company.