Recombinant Proteins for AlphaLISA and HTRF Assay Development

Aug 10, 2026

The best recombinant proteins for AlphaLISA and HTRF assay development match the target interaction, capture chemistry and detection orientation required by the assay. Biotinylated, Avi-tagged, His-tagged, Fc-tagged and active proteins provide flexible options for proximity-based binding, competition and protein–protein interaction studies. Beta LifeScience recombinant proteins are available across multiple species, expression systems and tagged formats. Researchers can compare catalog proteins or request technical evaluation when a project requires a specific sequence, tag position, biotinylation format, concentration or production scale.

Building an AlphaLISA or HTRF assay?

Compare biotinylated recombinant proteins by target, species, tag, purity, activity and expression system. If the required format is unavailable, submit the assay design through the project evaluation form.

Featured Recombinant Proteins to Compare

The following products are technically relevant candidates based on their tags, expression systems and documented activity. Their product pages do not necessarily report direct validation in AlphaLISA or HTRF assays.

Product	Catalog number and ordering	Production specifications	QC and documented activity
Biotinylated Human Fc gamma RI/CD64 Protein, Active	BLK-02123P-100UG; 100 µg; online inquiry	Human; HEK293; Gln16–Pro288; C-His-Avi; lyophilized	>95% by Tris-Bis PAGE and HPLC; endotoxin <1 EU/µg by LAL; SPR affinity constant: 0.91 nM
Biotinylated Human Fc gamma RIIB/CD32b Protein, Active	BLK-02406P-100UG; 100 µg; online inquiry	Human; HEK293; Ala46–Pro217; C-His-Avi; lyophilized	>95% by Tris-Bis PAGE and HPLC; endotoxin <1 EU/µg by LAL; SPR affinity constant: 3.97 µM
Biotinylated Mouse Fc gamma RIII/CD16 Protein, Active	BLK-00117P-100UG; 100 µg; online inquiry	Mouse; HEK293; Leu32–Thr215; C-His-Avi; lyophilized	>95% by Tris-Bis PAGE; endotoxin <1 EU/µg by LAL; SPR affinity constant: 0.164 µM
Biotinylated Human TNFSF14 Protein (hFc-Avi), Active	BLC-05828P; 20 µg; online inquiry	Human; mammalian cells; 74–240 aa; N-hFc-Avi; lyophilized powder	>90% by SDS-PAGE; endotoxin <1 EU/µg by LAL; functional ELISA binding to immobilized TNFRSF14; EC50 1.773–3.707 ng/mL

Important: Documented activity reflects the test listed on each product page and does not independently confirm compatibility with every AlphaLISA or HTRF configuration.

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Which Protein Format Fits the Assay Design?

Protein format	Potential assay role	Selection priority
Biotinylated protein	Capture through a compatible streptavidin system	Confirm delivered biotinylation status and binding activity
Avi-tagged protein	Controlled enzymatic biotinylation and oriented capture	Review tag position and biotinylation documentation
His-tagged protein	Capture through compatible anti-His reagents	Confirm that the tag remains accessible
Fc-tagged protein	Capture using Protein A, Protein G or anti-Fc reagents	Consider Fc-mediated dimerization and orientation
Dual-tagged protein	Provides alternative capture arrangements	Confirm accessibility of both tags
Tag-free protein	Analyte, competitor or control	Match the sequence and expression system to the tagged partner
Active protein	Ligand–receptor and functional binding studies	Review the exact documented activity method
Custom construct	Specialized domain, tag or sequence	Provide the complete assay design for evaluation

Selecting Proteins for AlphaLISA Assays

AlphaLISA is a bead-based proximity platform. Recombinant proteins can serve as captured targets, binding partners, analytes, competitors or controls. Beta LifeScience supplies recombinant protein components rather than AlphaLISA beads or complete assay kits. Platform-specific beads, buffers and detection equipment should be sourced for the selected technology.

Choose the Capture Arrangement First

Possible arrangements include:

Biotinylated receptor with an antibody-recognized ligand
Biotinylated antigen with a target-specific antibody
Avi-tagged receptor with an Fc-tagged ligand
Biotinylated protein with a His-tagged binding partner
Biotinylated probe with a tag-free competitor

When both interacting proteins use similar tags, confirm that the selected capture reagents can distinguish and orient each partner correctly.

Review Biotinylation and Tag Position

Biotinylation method can affect protein orientation. Avi-tagged formats support targeted enzymatic biotinylation, while random chemical labeling may modify multiple accessible residues.

Review these specifications before ordering:

Supplied biotinylation status
Avi-tag position
Additional purification tags
Protein sequence or expression range
Purity
Endotoxin level
Formulation
Documented binding or activity
Reconstitution instructions

An Avi tag in a product name identifies a potential biotinylation site. The product specification should confirm whether the delivered protein is supplied in a biotinylated format.

Preserve the Intended Interaction

The selected construct should include the region required for binding. For receptor–ligand assays, compare extracellular-domain boundaries, species, glycosylation requirements, oligomeric state and documented activity. Mammalian expression can be valuable when folding or post-translational modification contributes to the target interaction. The final selection should follow the biology of the target and the planned assay design.

Selecting Proteins for HTRF Assays

HTRF detects molecular proximity through compatible donor and acceptor fluorophores. Recombinant proteins can function as targets, interacting partners, competitors, standards or controls. Beta LifeScience supplies protein reagents that researchers can combine with platform-specific HTRF antibodies, fluorophores and detection components.

Match Tags to the Detection Reagents

Common protein formats include:

His-tagged proteins
Fc-tagged proteins
Avi-tagged or biotinylated proteins
Dual-tagged proteins
Tag-free competitors

A His-tagged protein may support detection with a compatible anti-His reagent. An Fc-tagged protein can provide an alternative capture route, although the Fc region may influence dimerization or protein orientation.

Tag position is particularly important in proximity assays. A tag located near the interaction interface may influence binding or capture. Compare N-terminal and C-terminal constructs where appropriate.

Include a Suitable Competitor or Control

A tag-free version of an interacting protein can support competition studies. Increasing the competitor concentration may reduce the proximity signal when it disrupts the captured interaction.

The competitor should match the required:

Species
Protein domain
Folding state
Glycosylation pattern
Oligomeric form
Biological activity

When an appropriate tag-free catalog format is unavailable, researchers can request technical evaluation for a custom construct.

AlphaLISA vs HTRF Protein Selection

Selection factor	AlphaLISA consideration	HTRF consideration
Capture format	Match protein tags to compatible bead chemistry	Match tags to donor/acceptor detection reagents
Biotinylated protein	Common option for streptavidin capture	Use when supported by the detection arrangement
His or Fc tag	Can provide an independent capture route	Can pair with compatible anti-tag reagents
Purity	Supports lower nonspecific interference	Supports clearer proximity-dependent detection
Biological activity	Important for functional binding studies	Important for interaction and inhibition studies
Expression system	Should support required folding and PTMs	Should preserve the measured interaction
Protein form	Confirm reconstitution and storage requirements	Confirm labeling and buffer compatibility
Customization	Useful for specialized domains and tag positions	Useful for competitor and control formats

Catalog Protein or Custom Production?

Requirement	Catalog protein	Custom or semi-custom request
Target and species already available	Recommended starting point	Consider when specifications differ
Required tag already available	Direct selection	Request evaluation of another tag or position
Standard extracellular domain works	Direct selection	Request evaluation of modified sequence boundaries
Pilot assay development	Listed size may be suitable	Consider when no catalog match exists
Tag-free competitor required	Select an available tag-free product	Request technical feasibility evaluation
Specific concentration needed	Confirm available formulation	Request evaluation of a defined concentration
Large screening campaign	Ask about available lot and bulk ordering	Request scale-up and lot planning
Specialized QC or activity requirement	Review current product documentation	Include the required test in the project brief

A catalog protein offers the most direct purchasing route when its target, species, sequence, tag and activity profile match the assay. Semi-custom protein production can be evaluated when an existing construct needs a different tag, expression host, concentration or formulation.

Browse Relevant Product Collections

Researchers can compare:

Assess each product individually. A collection assignment does not replace review of product-specific activity, purity, endotoxin, sequence and formulation information.

What to Include in a Quote or Project Request

Providing a complete project brief supports efficient product matching and quotation.

Include:

Target protein and binding partner
AlphaLISA or HTRF platform
Intended assay format
Capture and detection chemistry
Species and accession number
Required sequence or protein domain
Expression system
Required tag and tag position
Biotinylation requirement
Purity and endotoxin requirements
Biological activity method
Protein concentration and buffer
Pilot quantity and expected bulk quantity
Required documentation
Preferred delivery schedule

Submit these details through the project evaluation form. Technical review can compare the requested format with available catalog proteins and evaluate a semi-custom or custom route.

FAQs

Does Beta LifeScience sell complete AlphaLISA or HTRF kits?

The company supplies recombinant protein reagents that can be evaluated as assay components. Beads, platform-specific fluorophores, compatible antibodies and detection equipment should be sourced according to the selected assay technology.

Are the featured proteins validated for AlphaLISA or HTRF?

The featured product pages document their expression systems, tags, purity and activity methods. They do not necessarily document direct testing in AlphaLISA or HTRF assays. Configuration-specific validation remains essential.

Can a His-Avi protein support more than one assay orientation?

A His-Avi format can provide multiple capture possibilities when the tags remain accessible and compatible detection reagents are available. The final orientation should be established experimentally.

Should an Fc-tagged or His-tagged protein be selected?

Choose according to the capture chemistry and target biology. Fc tags can support capture and dimeric presentation, while His tags provide a compact detection handle. The interaction interface and required protein state should guide the selection.

Can a custom tag-free competitor be ordered?

A custom tag-free competitor can be requested when a suitable catalog format is unavailable. Submit the required species, sequence, expression host, purity, quantity and activity requirements for technical evaluation. Production feasibility should be confirmed before ordering.

How much protein should be ordered?

Calculate the amount from the protein concentration, reaction volume, number of wells, optimization rounds and screening scale. Include additional material for titration, controls and repeat experiments.

Compare Products or Request an Evaluation

A productive AlphaLISA or HTRF workflow starts with a protein pair that matches the molecular interaction and detection strategy. Compare target, species, construct boundaries, expression system, tags, biotinylation, purity, endotoxin and documented activity before ordering.

Browse recombinant proteins, compare biotinylated protein formats, or request a project evaluation for a catalog, semi-custom or custom protein recommendation.

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