Practical Guide to TSA Tyramide Signal Amplification: How to Select Reagents, Optimize the Workflow, and Reduce Background When Detection Signals Are Weak for Low-Abundance Targets
Practical Guide to TSA Tyramide Signal Amplification: How to Select Reagents, Optimize the Workflow, and Reduce Background When Detection Signals Are Weak for Low-Abundance Targets
1 What Is TSA Tyramide Signal Amplification?
TSA, or Tyramide Signal Amplification, is a signal amplification technique based on HRP (Horseradish Peroxidase)-catalyzed reactions. It is commonly used in IHC (Immunohistochemistry), ICC (Immunocytochemistry), ISH (In Situ Hybridization), FISH (Fluorescence In Situ Hybridization), and multiplex immunofluorescence detection. The core function of TSA is to generate high-density, localized fluorescent or biotin-labeled deposits near the target, thereby enhancing the detection signal of low-abundance targets.
TSA detection typically includes the following key steps:
Step | Function |
Primary antibody recognizes the target | Determines the specificity of detection |
HRP-conjugated secondary antibody binds to the primary antibody | Localizes the enzyme near the target |
Labeled tyramide/tyramide derivatives and H₂O₂ (Hydrogen Peroxide) are added | HRP catalyzes tyramide to form reactive intermediates |
Labeled tyramide deposits near the target | Generates a localized, high-density signal |
Washing, mounting, and imaging | Produces fluorescence or chromogenic detection results |
The signal amplification in TSA comes from the enzymatic catalytic activity of HRP. A single HRP molecule can catalyze the deposition of multiple labeled tyramide/tyramide derivative molecules near the target, making TSA more suitable than conventional fluorescent secondary antibody labeling for detecting low-expression or difficult-to-detect targets.
2 When Is TSA Suitable?
2.1 Recommended Use Cases for TSA
TSA is better suited for solving “insufficient signal” problems, especially in the following experimental scenarios:
Experimental Challenge | Value of TSA |
Low target expression | Amplifies the local signal and improves detectability |
Weak signal in conventional IF (Immunofluorescence) | Improves the signal-to-noise ratio in imaging |
Reduced antigenicity in FFPE (Formalin-Fixed Paraffin-Embedded) tissue | Enhances weak positive signals |
Multiplex immunofluorescence requiring multiple rounds of staining | Tyramide-deposited signals are relatively stable, facilitating subsequent antibody processing |
Multiple primary antibodies derived from the same host species | Sequential staining, antibody removal or inactivation, and termination of residual HRP activity can reduce the risk of secondary antibody cross-reactivity |
Precious samples | Helps obtain more target information from the same tissue section |
2.2 Situations Where TSA Is Not Recommended as the First Choice
TSA is not the preferred option for every experiment. It should be used with caution in the following situations:
① The target itself is highly abundant, and conventional secondary antibody detection already provides a clear signal.
② The sample has strong endogenous peroxidase activity, but sufficient quenching has not been performed.
③ The specificity of the primary antibody has not been verified; direct use of TSA may also amplify nonspecific background.
④ Multiplex staining is initiated directly without first validating single-marker staining.
⑤ Strict quantitative analysis is required, but the linear relationship between signal intensity and target abundance has not yet been confirmed.
The advantage of TSA is improved sensitivity, but it can also amplify background signals. Therefore, before using TSA, the specificity of the primary antibody, sample processing conditions, and control setup should first be confirmed.
3 How to Select TSA Reagents
3.1 Selection Based on Detection Method
TSA reagent selection should not be based only on fluorescence color. Detection method, target abundance, sample background, microscope channels, HRP detection system, and whether multiplex staining is required should all be considered. TSA reagents are generally divided into two categories: fluorescently labeled tyramide and biotin-labeled tyramide.
Type | Features | Suitable Applications |
Fluorescently labeled tyramide/tyramide derivatives | Can be imaged directly after deposition | Immunofluorescence, multiplex immunofluorescence, and colocalization analysis |
Biotin-Tyramide, or biotin-labeled tyramide | Requires further detection using a streptavidin-based system | Used when secondary amplification, enzymatic chromogenic detection, or a specific detection system is required |
Fluorescently labeled tyramide can be conjugated to different fluorophores, such as FITC (Fluorescein Isothiocyanate), TAMRA (Tetramethylrhodamine), Cy3, Cy5, and Alexa Fluor series dyes. Selection should be based on the microscope light source, filter sets, laser lines, and detector configuration.
3.2 Selection Based on Target Abundance
Different targets should be detected using strategies with different amplification strengths:
Target Abundance | Recommended Strategy |
High-abundance target | Conventional direct or indirect immunofluorescence is usually sufficient |
Medium-abundance target | Conventional secondary antibody detection can be used first, with mild amplification if needed |
Low-abundance target | Suitable for TSA enzymatic amplification |
Extremely low-abundance or difficult-to-detect target | Primary antibody, HRP-conjugated secondary antibody, tyramide concentration, and reaction time need to be optimized |
Low-abundance targets can be preferentially assigned to channels with high brightness, low background, and minimal spectral interference. High-abundance targets should not be over-amplified, as this may lead to excessively strong signals, blurred localization, or fluorescence bleed-through.
3.3 Selection Based on Multiplex Staining Design
In multiplex immunofluorescence experiments, TSA reagent selection should consider three factors:
① Spectral separation: spectral overlap between different fluorescent signals should be minimized.
② Target intensity: weak targets should be assigned to brighter and more stable fluorescence channels first.
③ Staining order: for targets that are more sensitive to antigen retrieval and antibody removal, staining order should be validated first.
Staining order should not be determined solely by target abundance. It should also be validated through pilot experiments based on the tolerance of each antigen to multiple rounds of heat-induced retrieval, antibody removal, or antibody inactivation. In multiplex experiments, each target should first be validated by single-marker staining to confirm localization, background, and exposure conditions before multiplex combinations are performed.
4 Basic TSA Experimental Workflow
4.1 Single-Marker TSA Workflow
The basic TSA workflow is similar to conventional IHC, ICC, or IF, but includes an additional HRP-catalyzed tyramide deposition step. If the sample is an FFPE tissue section, baking, deparaffinization, and rehydration are usually required before antigen retrieval. Fixation, permeabilization, and antigen retrieval conditions should be optimized separately for cells, frozen sections, and FFPE samples.
Workflow | Purpose |
Sample fixation and permeabilization | Preserves structure and exposes the target |
Antigen retrieval | Improves antigen accessibility in FFPE tissue |
Endogenous peroxidase quenching | Reduces nonspecific enzymatic background |
Blocking | Reduces nonspecific antibody binding |
Primary antibody incubation | Recognizes the target protein or nucleic acid-related target |
HRP-conjugated secondary antibody incubation | Localizes HRP near the target |
Labeled tyramide working solution incubation | Generates localized fluorescent or biotin deposition |
Washing and termination | Removes free reagents and reduces background |
Counterstaining, mounting, and imaging | Produces the final detection image |
4.2 Key Operational Considerations
The TSA reaction is sensitive to concentration and reaction time. The labeled tyramide working solution should generally be prepared fresh before use, and the reaction time should be optimized according to sample type, target abundance, and background level.
The following factors should be carefully controlled during the experiment:
① The primary antibody concentration should not be too high, as this may increase nonspecific signals.
② The HRP-conjugated secondary antibody concentration should be optimized; an excessive concentration may increase background.
③ Overly long labeled tyramide incubation may cause signal diffusion.
④ The H₂O₂ concentration should be prepared according to the reagent instructions.
⑤ Washing should be thorough to avoid residual free tyramide or antibody.
5 Common TSA Problems and Optimization Strategies
5.1 Weak Signal
Weak TSA signal is usually not caused by a single factor. Troubleshooting should cover four aspects: the target, primary antibody, HRP system, and tyramide reaction.
Possible Cause | Optimization Strategy |
Target expression is too low | Set up a positive control to confirm that the target is detectable |
Primary antibody is not suitable for IHC, ICC, or IF | Select a primary antibody validated for the intended application |
Primary antibody concentration is too low | Moderately increase the primary antibody concentration or extend the incubation time |
HRP-conjugated secondary antibody has insufficient activity | Replace the HRP-conjugated secondary antibody or check storage conditions |
Labeled tyramide has degraded | Use a freshly prepared working solution and protect it from light |
Reaction time is insufficient | Moderately extend the tyramide incubation time within the range recommended in the instructions |
5.2 High Background
TSA can amplify specific signals, but it may also amplify weak background signals. Background control is critical to the success of TSA experiments.
Possible Cause | Optimization Strategy |
Insufficient blocking | Extend the blocking time or optimize the blocking buffer |
Primary antibody concentration is too high | Reduce the primary antibody concentration |
HRP-conjugated secondary antibody concentration is too high | Reduce the HRP-conjugated secondary antibody concentration |
Endogenous peroxidase is not sufficiently quenched | Add or strengthen the peroxidase quenching step |
Tyramide reaction is too strong | Reduce the labeled tyramide concentration or shorten the incubation time |
Insufficient washing | Increase the number and duration of washes |
Negative controls are recommended, especially no-primary-antibody controls. If a clear signal is still observed in the no-primary-antibody control, endogenous peroxidase, endogenous biotin, tissue autofluorescence, and nonspecific secondary antibody binding should be checked first.
5.3 Signal Diffusion or Poor Localization
The ideal TSA result is a signal concentrated near the target. If diffuse fluorescence, unclear cell boundaries, or abnormal subcellular localization occurs, the amplification reaction is usually too strong.
The following adjustments can be made:
① Shorten the labeled tyramide incubation time.
② Reduce the concentration of the labeled tyramide working solution.
③ Reduce the concentration of the HRP-conjugated secondary antibody.
④ Reduce the primary antibody concentration.
⑤ Shorten the exposure time to avoid overexposure during imaging.
When localization is unclear, the issue should not be addressed first by increasing exposure or enhancing image contrast. Instead, the staining conditions themselves should be optimized.
5.4 Spectral Bleed-Through or Cross-Reactivity in Multiplex Staining
Common problems in multiplex TSA experiments include fluorescence bleed-through, antibody carryover from the previous round, and interference from strong targets with weak targets. Key optimization strategies include:
Problem | Solution |
Fluorescence bleed-through | Select fluorophore combinations with greater spectral separation |
Antibody carryover from the previous round | Optimize antibody removal or HRP inactivation steps |
One channel is too bright | Reduce the antibody concentration or tyramide reaction strength for that target |
Weak target is interfered with by a strong signal | Assign weak targets to high-brightness, low-background channels first |
Multiplex localization is difficult to interpret | Confirm single-marker images for each target first |
Multiplex staining should include single-marker controls, single-color controls, no-primary-antibody controls, and necessary spectral compensation or unmixing settings. For multi-round TSA staining, it is recommended to include a carryover control from the previous round. Specifically, after completing one round of staining and antibody removal or inactivation, omit the primary antibody in the next round and add only the corresponding HRP-conjugated secondary antibody and TSA substrate to confirm that residual antibody or HRP from the previous round does not cause false-positive signals. Without single-marker validation and necessary carryover controls, it is difficult to determine whether multiplex results are truly specific.
6 Design Principles for TSA Multiplex Immunofluorescence
6.1 Validate Single Markers Before Multiplex Staining
TSA multiplex immunofluorescence should not begin directly with a mixture of multiple antibodies. A reasonable workflow is as follows:
① Validate the specificity and localization of each primary antibody separately.
② Confirm the relative expression level of each target in the sample.
③ Determine the exposure conditions for each fluorescence channel.
④ Then proceed with multiplex combination design.
The purpose of single-marker validation is not to obtain the final data, but to rule out basic problems such as unsuitable antibodies, high background, and abnormal localization.
6.2 Assign Channels According to Target Strength
In multiplex experiments, weak targets should be assigned to higher-sensitivity TSA channels first. Strong targets should avoid excessively strong amplification conditions, as they may obscure weak signals or reduce the dynamic range of the image.
Target Type | Recommended Arrangement |
Weakly expressed target | Use a high-brightness fluorescence channel and optimize it first |
Moderately expressed target | Use standard TSA conditions or moderate amplification |
Strongly expressed target | Reduce antibody concentration or shorten the tyramide reaction time |
Target requiring fine localization | Avoid over-amplification and prioritize spatial resolution |
6.3 Control Carryover in Each Round of Staining
In multi-round TSA staining, residual antibody, HRP activity, or free reagents from the previous round may affect subsequent channels. After each round, ensure that:
① HRP activity has been effectively terminated.
② The primary and secondary antibodies from the previous round have been sufficiently removed or inactivated.
③ Washing is sufficient and no free tyramide remains.
④ The imaging result of the current channel meets expectations before proceeding to the next round.
7 Pre-Experiment Checklist for TSA
Before formally starting a TSA experiment, the following items should be checked one by one:
Checklist Item | Evaluation Criterion |
Target abundance | Whether signal amplification is truly needed |
Primary antibody suitability | Whether the antibody has been validated for IHC, ICC, IF, ISH, or FISH |
Positive control | Whether it can demonstrate that the target is detectable |
Negative control | Whether it can assess nonspecific background |
HRP-conjugated secondary antibody | Whether it matches the host species of the primary antibody and the experimental system |
Endogenous peroxidase | Whether necessary quenching has been completed |
Tyramide working solution | Whether it is freshly prepared and protected from light |
Incubation time | Whether it has been optimized through pilot experiments |
Fluorescence channel | Whether it is compatible with the microscope configuration |
Multiplex staining | Whether single-marker and single-color controls have been completed |
Autofluorescence control | Whether the intrinsic background fluorescence level of the sample is understood |
Multi-round carryover control | In multi-round TSA staining, whether residual antibody or HRP from the previous round has been confirmed not to affect subsequent channels |
8 Representative Product Categories and Application Recommendations Related to TSA Tyramide Signal Amplification
Table 1 TSA Core Substrates and Enzymatic Amplification Reaction Products
Category | CAS No. | Aladdin Cat. No. | Name | Specification or Purity | Product Features and Applications |
Basic tyramide raw material | 51-67-2 | Tyramide | Moligand™, ≥98% | Used for the synthesis of tyramide-based substrates, preparation of tyramide derivatives, and research on enzymatic deposition reactions | |
Tyramide salt-form raw material | 60-19-5 | Tyramide hydrochloride | ≥98% | Used for the preparation of tyramide-based labeling substrates, research on enzymatic reaction conditions, and development of signal amplification systems | |
Biotin-tyramide substrate | 41994-02-9 | Biotinyl tyramide | ≥98% (HPLC) | Used for horseradish peroxidase-catalyzed deposition, biotin–avidin detection systems, and signal amplification of low-abundance targets | |
Fluorescent tyramide substrate | — | Cyanine 3 Tyramide methyl indole | ≥98% | Used for tyramide signal amplification, multiplex immunofluorescence, target localization in tissue sections, and weak-signal imaging | |
Fluorescent tyramide substrate | — | Cyanine 5 Tyramide methyl indole | ≥95% | Used for far-red channel tyramide deposition, multiplex immunofluorescence combinations, and detection of low-abundance targets | |
Ready-to-use fluorescent tyramide substrate | — | Ready-to-use LumiDye™ 540 Tyramide (200×) | BioReagent, for microscopy, biological stain, suitable for fluorescence analysis, suitable for immunohistochemistry (for IHC), suitable for immunofluorescence (IF), for ELISA, ready-to-use | Used for tyramide signal amplification in immunohistochemistry, immunofluorescence, enzyme-linked detection, and microscopic imaging | |
Near-infrared fluorescent tyramide substrate | — | Cyanine CY7 Tyramide | ≥98% | Used for near-infrared channel tyramide deposition, multiplex immunofluorescence, and target detection in tissue samples | |
Tyramide amplification buffer | — | Tyramide Amplification Buffer | BioReagent, ready-to-use, suitable for immunofluorescence (IF) | Used for fluorescent tyramide deposition reactions, immunofluorescence detection, and tissue staining amplification workflows | |
Peroxidase quenching/reaction supporting reagent | 7722-84-1 | Hydrogen peroxide solution | Suitable for microbiology, 3% | Mainly used for endogenous peroxidase quenching; if used in an HRP-catalyzed TSA reaction system, it should be diluted and optimized according to the specific formulation or reagent instructions |
Table 2 HRP Enzyme-Linked, Avidin/Streptavidin System, and Antibody Detection Products
Category | CAS No. | Aladdin Cat. No. | Name | Specification or Purity | Product Features and Applications |
Biotinylated enzyme | 9003-99-0 | Biotinylated Horseradish Peroxidase | Carrier-free, azide-free, EnzymoPure™, 1.0 mg/mL | Used for constructing biotin–avidin systems, horseradish peroxidase-catalyzed reactions, and signal amplification detection | |
Affinity protein | 9013-20-1 | Streptavidin | BioReagent, ≥98% | Used for binding biotin-tyramide deposition sites and affinity capture; if imaging, chromogenic, or chemiluminescent signal output is required, it should be used together with fluorescent labeling, enzyme labeling, or another detection system | |
Affinity protein | 1405-69-2 | Avidin from egg white | ≥98%, lyophilized powder, 10–15 units/mg protein (E1%/280) | Used for recognition of biotin-labeled molecules and affinity capture; when used in tissue staining systems, it should be combined with an appropriate signal output system, and endogenous biotin background should be considered | |
HRP-labeled affinity protein | — | HRP-conjugated Streptavidin | High performance, azide-free, 1.0 mg/mL | Used for recognizing biotin-tyramide deposition signals, enzymatic detection, and tissue staining amplification | |
HRP-labeled affinity protein | — | HRP-Streptavidin | — | Used for detection of biotinylated targets, biotin-tyramide systems, and enzymatic signal output | |
HRP-labeled NeutrAvidin | — | HRP-conjugated NeutrAvidin | ExactAb™, validated, 1.0 mg/mL | Used for biotin-system detection, signal recognition after tyramide amplification, and target detection in tissue samples | |
HRP-conjugated secondary antibody | — | Goat Anti-Chicken IgY H&L (HRP) | ExactAb™, high performance, validated, azide-free, 1.0 mg/mL | Used for detecting chicken primary antibodies, tyramide signal amplification, and tissue immunostaining | |
HRP-conjugated secondary antibody | — | Goat Anti-Human IgG H&L (HRP) | ExactAb™, high performance, validated, 1 mg/mL | Used for detecting human IgG or human primary antibody-related systems, tyramide deposition reactions, and immunoassays | |
HRP-conjugated secondary antibody | — | Goat Anti-Mouse IgG H&L (HRP) | ExactAb™, azide-free, validated, high performance, pre-adsorbed, 1.0 mg/mL | Used for detecting mouse primary antibodies, immunofluorescence amplification, and immunohistochemistry detection | |
HRP-conjugated secondary antibody | — | Goat Anti-Rabbit IgG H&L (HRP) | ExactAb™, azide-free, validated, high performance, pre-adsorbed, 1.0 mg/mL | Used for detecting rabbit primary antibodies, low-abundance target amplification, and multiplex staining workflows | |
HRP-labeled tag antibody | — | HA tag Mouse mAb (HRP) | ExactAb™, validated, high performance, 0.5 mg/mL | Used for tag protein detection, recombinant protein localization, and tyramide-amplified imaging | |
HRP antibody labeling tool | — | HRP Antibody Labeling Kits | — | Used for preparing horseradish peroxidase-labeled antibodies, establishing tyramide amplification detection workflows, and building antibody detection systems | |
HRP conjugate stabilizer | — | Stabilizer for HRP conjugates | STplus | Used for storage of horseradish peroxidase conjugates, enzyme-labeled antibodies, and enzyme-labeled avidin/streptavidin systems | |
HRP conjugate stabilizer | — | HRP-StabilPLUS | Ready-to-use (RTU) | Used for storage of horseradish peroxidase conjugates, maintenance of enzymatic detection systems, and reagent stability control |
Table 3 Supporting Products for Buffers, Antigen Retrieval, Blocking, and Permeabilization
Category | CAS No. | Aladdin Cat. No. | Name | Specification or Purity | Product Features and Applications |
Phosphate buffer component | 7778-77-0 | Potassium phosphate monobasic | Anhydrous grade, UltraBio™, molecular biology grade, ≥99.5% (T) | Used for preparing phosphate buffers, washing buffers, and tissue staining reaction systems | |
Citrate antigen retrieval component | 5949-29-1 | Citric acid monohydrate | Reagent grade, ≥98% (GC/T) | Used for preparing antigen retrieval solutions for paraffin-embedded tissue sections and for antigen exposure before staining | |
Citrate antigen retrieval component | 6132-04-3 | Sodium citrate tribasic dihydrate | European Pharmacopoeia (Ph.Eur), suitable for analysis, ACS, premium grade | Used for citrate antigen retrieval buffers, tissue sample pretreatment, and pretreatment before immunostaining | |
Washing buffer surfactant | 9005-64-5 | Tween® 20 | Molecular biology grade, viscous liquids | Used for preparing washing buffers and reducing nonspecific residues of antibodies and free substrates | |
Inorganic buffer salt | 7647-14-5 | Sodium chloride | Molecular biology grade, ≥99.5% (AT) | Used for osmotic pressure adjustment in buffers, washing buffer preparation, and blocking system formulation | |
Inorganic buffer salt | 7447-40-7 | Potassium chloride | Molecular biology grade, ≥99.5% | Used for phosphate buffer preparation, cell sample processing, and maintenance of staining systems | |
Protein blocking agent | 9048-46-8 | Bovine Serum Albumin (BSA) | Low endotoxin, protease-free, ≥98%, lyophilized | Used for antibody diluent preparation, tissue blocking, and control of nonspecific binding | |
Tris buffer component | 1185-53-1 | Tris(hydroxymethyl)aminomethane hydrochloride (Tris HCl) | Ultrapure grade, ≥99% (T), useful in pH range 7.0–9.0 | Used for preparing washing buffers, antibody diluents, and staining reaction buffers | |
Blocking and antibody processing reagent | 56-40-6 | Glycine | UltraBio™, molecular biology grade, ultrapure grade, ≥99% (NT) | Used for antibody processing, blocking systems, aldehyde-related background control, and tissue staining workflows | |
Phosphate buffer component | 7558-79-4 | Sodium phosphate dibasic | UltraBio™, molecular biology grade, ≥99.5% (T) | Used for phosphate buffers, washing buffers, reaction solutions, and sample processing buffers | |
Cell permeabilization reagent | 9002-93-1 | Triton™ X-100 | UltraBio™, ultrapure grade | Used for cell membrane permeabilization, tissue sample processing, and immunostaining of intracellular targets | |
Ready-to-use buffer | 77-86-1 | Tris buffer | 1.0 M, pH 8.0, molecular biology grade | Used for antibody dilution, washing, and preparation of tyramide amplification-related buffer systems | |
Chelating antigen retrieval component | 6381-92-6 | Ethylenediaminetetraacetic acid disodium salt dihydrate | GR, ≥99% | Used for chelation-based antigen retrieval buffers, sample processing, and staining condition optimization | |
Fluorescent substrate solvent | 67-68-5 | Dimethyl sulfoxide | ≥99.9%, Ultra dry, water ≤50 ppm | Used for preparing stock solutions of hydrophobic fluorescent substrates, dyes, and related small-molecule reagents |
Table 4 Background Control, Nuclear Counterstaining, and Fluorescence Preservation Products
Category | CAS No. | Aladdin Cat. No. | Name | Specification or Purity | Product Features and Applications |
Nuclear counterstain | 23491-52-3 | Hoechst 33342 Staining Solution | Suitable for immunofluorescence (IF), BioReagent, ready-to-use, biological stain, suitable for fluorescence analysis, biological dye grade, for microscopy, for cell culture, 1.0 mg/mL in H₂O | Used for immunofluorescence imaging, nuclear staining of live or fixed cells, and nuclear localization in tissue sections | |
Autofluorescence suppression reagent | 4197-25-5 | Sudan Black B | Biological stain | Used for reducing autofluorescence in tissue samples, treating lipofuscin-related background, and controlling background in fluorescence imaging | |
Antifade component | 106-50-3 | p-Phenylenediamine | Sublimed grade, ≥99% | Used in fluorescence mounting systems, preservation of multiplex fluorescence signals, and preparation of samples for microscopic imaging | |
Aldehyde reduction and background control reagent | 16940-66-2 | S432207 | Sodium borohydride (explosive precursor) | purum p.a., ≥96% | Used for aldehyde reduction in fixed samples, autofluorescence treatment, and tissue background reduction |
Antifade component | 280-57-9 | 1,4-Diazabicyclo[2.2.2]octane (DABCO) | Moligand™, ≥98% | Used in fluorescence mounting media, signal preservation, and preparation of samples for microscopic imaging | |
Nuclear counterstain | 23491-45-4 | Hoechst 33258 Staining Solution | BioReagent, biological stain, biological dye grade, suitable for immunofluorescence (IF), suitable for fluorescence analysis, for cell culture, for microscopy, ready-to-use, 1.0 mg/mL in H₂O | Used for nuclear localization in fixed cells, tissue sections, and immunofluorescence samples | |
Nuclear counterstain | 28718-90-3 | 4′,6-Diamidino-2-phenylindole dihydrochloride | ≥98% | Used for immunofluorescence counterstaining, nuclear localization in tissue sections, and interpretation of multiplex imaging results |
Table 5 HRP Chromogenic, Chemiluminescent, and Extended Detection Products
Category | CAS No. | Aladdin Cat. No. | Name | Specification or Purity | Product Features and Applications |
HRP chromogenic substrate | 54827-17-7 | 3,3′,5,5′-Tetramethylbenzidine (TMB) | Standard for GC, ≥99% (GC) | Used for horseradish peroxidase chromogenic reactions, enzyme-linked detection, microplate reading, and evaluation of enzymatic detection systems | |
HRP precipitating chromogenic substrate | 7411-49-6 | 3,3′-Diaminobenzidine tetrahydrochloride | ≥99% | Used for immunohistochemical chromogenic detection, horseradish peroxidase detection, and target localization in tissue sections | |
HRP precipitating chromogenic substrate | 91-95-2 | 3,3′-Diaminobenzidine (DAB) | ≥99% | Used for immunohistochemistry, target localization in tissue sections, and horseradish peroxidase chromogenic detection | |
HRP microplate chemiluminescent substrate | — | HRP Microplate Chemiluminescent Substrate | — | Used for horseradish peroxidase-based microplate chemiluminescent detection, microplate signal reading, and evaluation of antibody detection systems | |
HRP microplate chemiluminescent substrate diluent | — | HRP Microplate Chemiluminescent Substrate Diluent | — | Used for preparing working solutions of horseradish peroxidase microplate chemiluminescent substrates and optimizing microplate detection systems | |
HRP membrane chemiluminescent substrate | — | HRP Membrane Chemiluminescent Substrate | — | Used for membrane chemiluminescent detection, visualization of enzyme-labeled antibody signals, and antibody performance verification |
Note: The products listed above are representative Aladdin products. For more product specifications, please search by “product name/CAS/catalog number” on the Aladdin website.
For more related articles, please see below:
Horseradish Peroxidase (HRP) — Structural Features, Enzymatic Properties and Application Overview
Sodium Azide–Free Biological Reagents
Professional Guide to Streptavidin-Modified Proteins
How to Elute Biotinylated Proteins and Nucleic Acids from Streptavidin Beads？
How Biotinylated Molecules are Purified with Streptavidin Beads
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