Bromodomain Assay Service (Reader Domain Assays)

Bromodomain screening and profiling of reader domains such as Tudor and chromodomains are performed at Reaction Biology via Thermo Shift, HTRF and AlphaScreen assays.

More than 85 bromodomain assays and 30 other epigenetic reader domain assays are available for screening, lead optimization, or selectivity profiling for reader domain inhibitors.

Several potent bromodomain inhibitors have recently been identified, increasing the appreciation of the reader domain family’s functional importance and therapeutic potential.

At Reaction Biology, we are continuously developing new reader domain assays.

Extensive coverage of the bromodomain family. We feature the largest bromodomain assay panel in the industry.
All bromodomain proteins and other reader domain proteins are produced at our facility and are available for purchase.
The BromoMELT^TM assay kit is available for in-house bromodomain inhibitor screening for selectivity profiling.
Reader domain inhibitor screening is performed with AlphaScreen, HTRF or Thermal shift assay formats.

Reaction Biology performs bromodomain assay services at our screening facility in Malvern, Pennsylvania. Our reader domain assay service’s typical turnaround time is 10 business days. Reach out to the business development manager in your area to receive a quotation.

Contact an expert

Meet us at your next conference

The Largest Bromodomain Assay Panel in Industry

Bromodomain proteins are epigenetic readers that bind to acetylated lysine residues on histones and regulate gene transcription. The phylogenetic tree shows the relationships between genes predicted to encode for bromodomain proteins.

all bromodomain containing epigenetic targets shown as a phylogenetic treee

List of Targets (121 total)

Target	HGNC Symbol	Synonym	Assay Format	Reader domains present in construct
ASH1L-[BRD]-GST	ASH1L	Bromodomain-containing ASH-1 like protein	ThermoShift	BRD
ATAD2-His	ATAD2	ATPase family AAA domain-containing protein 2	ThermoShift; AlphaScreen	BRD
ATAD2B-GST	ATAD2B	ATPase family AAA domain-containing protein 2B	ThermoShift	BRD
ATAD2B-His	ATAD2B	ATPase family AAA domain-containing protein 2B	ThermoShift; AlphaScreen	BRD
BAZ1A-GST	BAZ1A	hACF1; WCRF180; hWALp1	ThermoShift	BRD
BAZ1B-His	BAZ1B	Bromodomain adjacent to zinc finger domain protein 1B	ThermoShift; AlphaScreen	BRD
BAZ2A-GST	BAZ2A	Bromodomain adjacent to zinc finger domain protein 2A	ThermoShift	BRD
BAZ2A-His	BAZ2A	Bromodomain adjacent to zinc finger domain protein 2A	AlphaScreen	BRD
BAZ2B-His	BAZ2B	Bromodomain adjacent to zinc finger domain protein 2B	ThermoShift; AlphaScreen	BRD
BPTF-[BRD]-His	BPTF	Bromodomain-containing transcription factor	ThermoShift; AlphaScreen	BRD
BPTF-[PHD-BRD]-His	BPTF	Bromodomain and PHD finger-containing transcription factor	AlphaScreen; ThermoShift	BRD; PHD
BRD1-GST	BRD1	Bromodomain-containing protein 1	ThermoShift	BRD
BRD1-His	BRD1	Bromodomain-containing protein 1	ThermoShift; AlphaScreen	BRD
BRD2-1-GST	BRD2	Bromodomain-containing protein 2 domain 1	ThermoShift	BRD
BRD2-1-His	BRD2	Bromodomain-containing protein 2 domain 1	ThermoShift; AlphaScreen	BRD
BRD2-2-GST	BRD2	Bromodomain-containing protein 2 domain 1	ThermoShift	BRD
BRD2-2-His	BRD2	Bromodomain-containing protein 2 domain 2	ThermoShift; AlphaScreen	BRD
BRD2-Tndm-His	BRD2	Bromodomain-containing protein 2 domain 1 and domain 2	ThermoShift; AlphaScreen	BRD
BRD3-1-GST	BRD3	Bromodomain-containing protein 3 domain 1	ThermoShift	BRD
BRD3-1-His	BRD3	Bromodomain-containing protein 3 domain 1	ThermoShift; AlphaScreen	BRD
BRD3-2-GST	BRD3	Bromodomain-containing protein 3 domain 2	ThermoShift	BRD
BRD3-2-His	BRD3	Bromodomain-containing protein 3 domain 2	ThermoShift; AlphaScreen	BRD
BRD3-Tndm-GST	BRD3	Bromodomain-containing protein 3 domain 1 and domain 2	ThermoShift	BRD
BRD3-Tndm-His	BRD3	Bromodomain-containing protein 3 domain 1 and domain 2	ThermoShift; AlphaScreen	BRD
BRD4 Full length	BRD4	Bromodomain-containing protein 4, full length	ThermoShift AlphaScreen	BRD
BRD4-1	BRD4	Bromodomain-containing protein 4 domain 1	SPR	BRD
BRD4-1-GST	BRD4	Bromodomain-containing protein 4 domain 1	ThermoShift	BRD
BRD4-1-His	BRD4	Bromodomain-containing protein 4 domain 1	ThermoShift; AlphaScreen	BRD
BRD4-2	BRD4	Bromodomain-containing protein 4 domain 2	SPR	BRD
BRD4-2-GST	BRD4	Bromodomain-containing protein 4 domain 2	ThermoShift	BRD
BRD4-2-His	BRD4	Bromodomain-containing protein 4 domain 2	ThermoShift; AlphaScreen	BRD
BRD4-Tndm-GST	BRD4	Bromodomain-containing protein 4 domain 1 and 2	ThermoShift	BRD
BRD4-Tndm-His	BRD4	Bromodomain-containing protein 4 domain 1 and 2	ThermoShift; AlphaScreen	BRD
BRD7-GST	BRD7	BP75; CELTIX-1	ThermoShift	BRD
BRD9-GST	BRD9	Bromodomain-containing protein 9	ThermoShift	BRD
BRD9-His	BRD9	Bromodomain-containing protein 9	ThermoShift; AlphaScreen	BRD
BRDT-1-His	BRDT	Bromodomain testis-specific protein domain 1	ThermoShift; AlphaScreen	BRD
BRDT-2-His	BRDT	Bromodomain testis-specific protein domain 2	ThermoShift	BRD
BRDT-Tndm-His	BRDT	Bromodomain testis-specific protein domain 1 and domain 2	ThermoShift; AlphaScreen	BRD
BRPF1a	BRPF1	Bromodomain and PHD finger-containing protein 1, isoform 1	ThermoShift	BRD
BRPF1b-GST	BRPF1	Bromodomain and PHD finger-containing protein 1, isoform 2	ThermoShift	BRD
BRPF1b-His	BRPF1	Bromodomain and PHD finger-containing protein 1, isoform 2	ThermoShift; AlphaScreen	BRD
BRPF3-GST	BRPF3	Bromodomain and PHD finger-containing protein 3	ThermoShift	BRD
BRPF3-His	BRPF3	Bromodomain and PHD finger-containing protein 3	ThermoShift; AlphaScreen	BRD
BRWD1-2-GST	BRWD1	Bromodomain and WD repeat-containing protein 1-Bromodomain 2	ThermoShift	BRD
BRWD1-2-His	BRWD1	Bromodomain and WD repeat-containing protein 1-Bromodomain 2	ThermoShift; AlphaScreen	BRD
BRWD3-2-GST	BRWD3	Bromodomain and WD repeat-containing protein 3-Bromodomain 2	ThermoShift	BRD
CBX7-[CHR]-GST	CBX7	Chromobox 7 chromodomain	ThermoShift	CHR
CDg1-[CHR]-GST	CDY1	chromodomain Y-linked 1 chromodomain	ThermoShift	CHR
CECR2-GST	CECR2	Cat eye syndrome critical region protein 2	ThermoShift	BRD
CECR2-His	CECR2	Cat eye syndrome critical region protein 2	AlphaScreen; ThermoShift	BRD
CHD1-[CHR]-GST	CHD1	chromodomain helicase DNA binding protein 1 chromodomain	ThermoShift	CHR
CHD1-[CHR]-His	CHD1	chromodomain helicase DNA binding protein 1 chromodomain	ThermoShift	CHR
CHD2-[CHR]-GST	CHD2	chromodomain helicase DNA binding protein 2 chromodomain	ThermoShift	CHR
CHD2-[CHR]-His	CHD2	chromodomain helicase DNA binding protein 2 chromodomain	ThermoShift	CHR
CHD4-[CHR]-GST	CHD4	chromodomain helicase DNA binding protein 4 chromodomain	ThermoShift	CHR
CHD4-[PHD-CHR]-GST	CHD4	chromodomain helicase DNA binding protein 4 PHD domain and chromodomain	ThermoShift	CHR; PHD
CHD7-[CHR]-GST	CHD7	chromodomain helicase DNA binding protein 4 chromodomain	ThermoShift	CHR
CREBBP-GST	CREBBP	CREB-binding protein	ThermoShift	BRD
CREBBP-His	CREBBP	CREB-binding protein	ThermoShift; AlphaScreen	BRD
EED	EED	Polycomb protein EED, embryonic ectoderm development	HTRF	WDR
EP300-GST	EP300	Histone acetyltransferase p300, E1A-associated protein p300	ThermoShift	BRD
EP300-His	EP300	Histone acetyltransferase p300, E1A-associated protein p300	ThermoShift	BRD
HP1alpha-[CHR]-His	CBX5	HP1a, Chromobox 5 chromodomain	ThermoShift	CHR
HP1alpha-GST	CBX5	HP1a, Chromobox 5	ThermoShift	CHR
HP1beta-[CHR]-GST	CBX1	HP1b, Chromobox 1 chromodomain	ThermoShift	CHR
HP1beta-[CHR]-His	CBX1	HP1b, Chromobox 1 chromodomain	AlphaScreen*; ThermoShift	CHR
HP1beta-GST	CBX1	HP1b, Chromobox 1	ThermoShift	CHR
HP1beta-His	CBX1	HP1b, Chromobox 1	AlphaScreen*; ThermoShift	CHR
HP1beta-Strep	CBX1	HP1b, Chromobox 1	ThermoShift	CHR
HP1gamma-GST	CBX3	Chromobox 3	ThermoShift	CHR
HP1gamma-His	CBX3	Chromobox 3	ThermoShift	CHR
KAT2A	KAT2A	lysine acetyltransferase 2A	ThermoShift	BRD
KAT2B	KAT2B	lysine acetyltransferase 2B	ThermoShift	BRD
KAT5-2-[CHR]-His	KAT5	lysine acetyltransferase 5 transcript variant 2 chromodomain	ThermoShift	CHR-like
KAT5-3-[CHR]-GST	KAT5	lysine acetyltransferase 5 transcript variant 3 chromodomain	ThermoShift	CHR-like
KAT5-3-[CHR]-His	KAT5	lysine acetyltransferase 5 transcript variant 3 chromodomain	ThermoShift	CHR-like
L3MBTL1	L3MBTL1	lethal(3)malignant brain tumor-like protein 1	ThermoShift	MBT
L3MBTL1-His	L3MBTL1	lethal(3)malignant brain tumor-like protein 1	AlphaScreen	MBT
L3MBTL3-His	L3MBTL3	lethal(3)malignant brain tumor-like protein 3	AlphaScreen	MBT
MPP8-[CHR]-GST	MPHOSPH8	M-phase phosphoprotein 8 chromodomain	ThermoShift	CHR
PB1-1	PBRM1	polybromo 1, PBRM1 bromodomain 1	ThermoShift	BRD
PB1-2	PBRM1	polybromo 1, PBRM1 bromodomain 2	ThermoShift	BRD
PB1-3	PBRM1	polybromo 1, PBRM1 bromodomain 3	ThermoShift	BRD
PB1-4	PBRM1	polybromo 1, PBRM1 bromodomain 4	ThermoShift	BRD
PB1-5	PBRM1	polybromo 1, PBRM1 bromodomain 5	ThermoShift	BRD
PB1-6	PBRM1	polybromo 1, PBRM1 bromodomain 6	ThermoShift	BRD
PHIP-2	PHIP	pleckstrin homology domain interacting protein bromodomain 2	ThermoShift	BRD
PHIP-Tndm	PHIP	pleckstrin homology domain interacting protein tandem bromodomains	ThermoShift	BRD
SMARCA2a bromodomain	SMARCA2	SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 2 bromodomain	HTRF	BRD
SMARCA2a-His	SMARCA2	SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 2	ThermoShift	BRD
SMARCA2b-His	SMARCA2	SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 2	AlphaScreen*; ThermoShift	BRD
SMARCA4-His	SMARCA4	SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 4	ThermoShift; AlphaScreen	BRD
SP100-GST	SP100	SP100 nuclear antigen	ThermoShift	BRD
SP100-His	SP100	SP100 nuclear antigen	ThermoShift	BRD
SP110c-GST	SP110	SP110 nuclear body protein	ThermoShift	BRD
SP140-GST	SP140	SP140 nuclear body protein	ThermoShift	BRD
SP140-His	SP140	SP140 nuclear body protein	ThermoShift; AlphaScreen	BRD
SP140L-GST	SP140L	SP140 nuclear body protein like	ThermoShift	BRD
SP140L-His	SP140L	SP140 nuclear body protein like	ThermoShift; AlphaScreen	BRD
TAF1-1-GST	TAF1	TATA-box binding protein associated factor 1, TBP-associated factor, bromodomain 1	ThermoShift	BRD
TAF1-2-GST	TAF1	TATA-box binding protein associated factor 1, TBP-associated factor, bromodomain 2	ThermoShift	BRD
TAF1-2-His	TAF1	TATA-box binding protein associated factor 1, TBP-associated factor, bromodomain 2	AlphaScreen	BRD
TAF1L-1	TAF1L	TAF1-like bromodomain 1	ThermoShift	BRD
TAF1L-2	TAF1L	TAF1-like bromodomain 2	ThermoShift	BRD
TAF1L-Tndm-GST	TAF1L	TAF1-like tandem bromodomains	ThermoShift	BRD
TRIM24	TRIM24	tripartite motif containing 24	ThermoShift	BRD
TRIM28	TRIM28	tripartite motif containing 28	ThermoShift	BRD
TRIM33a	TRIM33	tripartite motif containing 33 transcript variant a	ThermoShift	BRD
TRIM33b-His	TRIM33	tripartite motif containing 33 transcript variant a	ThermoShift	BRD
TRIM66	TRIM66	tripartite motif containing 66	ThermoShift	BRD
UHRF1 Full length	UHRF1	ubiquitin like with PHD and ring finger domains 1 full length	ThermoShift	PHD; TDR; SRA
UHRF1-[PHD]	UHRF1	ubiquitin like with PHD and ring finger domains 1 PHD	ThermoShift	PHD
UHRF1-[PHD]-His	UHRF1	ubiquitin like with PHD and ring finger domains 1 PHD	AlphaScreen*	PHD
UHRF1-[SRA]	UHRF1	ubiquitin like with PHD and ring finger domains 1 SRA dmain	ThermoShift	SRA
UHRF1-[TDR-PHD]	UHRF1	ubiquitin like with PHD and ring finger domains 1 tudor domain and PHD	ThermoShift	PHD; TDR
UHRF1-[TDR-PHD]-His	UHRF1	ubiquitin like with PHD and ring finger domains 1 tudor domain and PHD	AlphaScreen*	PHD; TDR
UHRF1-[TDR]-His	UHRF1	ubiquitin like with PHD and ring finger domains 1 tudor domain	AlphaScreen*; ThermoShift	TDR
UHRF1-His Full length	UHRF1	ubiquitin like with PHD and ring finger domains 1 full length	AlphaScreen*	PHD; TDR; SRA
YTHDF1	YTHDF1	YTH domain-containing family protein 1, C20orf21, DF1, Dermatomyositis associated with cancer putative autoantigen 1, DACA1	HTRF	RNA Me
YTHDF2	YTHDF2	HGRG8, CLL-associated antigen KW-14, High-glucose-regulated protein 8, Renal carcinoma antigen NY-REN-2	HTRF	RNA Me

* no small molecule control available

BRD… Bromodomain; read acetyl-lysines
CHR … Chromodomain; read methyl-lysines
PHD … Plant homeodomain; read methyl-lysines, acetylated-lysines, methyl-arginines, unmodified lysines
MBT … Malignant brain tumor domain; read methyl- lysines
TDR … Tudor domain; read methyl-lysines and methyl-arginines
WDR … WD40-repeat domain; versatile binding
SRA … SET- and RING-associated domain; read methyl-cytosine

Source: SGC, Chromohub (http://apps.thesgc.org/resources/phylogenetic_trees/)

Assay Details

Assay format: AlphaScreen

AlphaScreen assays stand for amplified luminescent proximity homogeneous assay.

Example of bromodomain BRD-1: The His-tagged bromodomain and the substrate, which is a biotin-tagged acetylated peptide, are each captured on AlphaScreen beads. Binding interaction between the peptide and the bromodomain brings the beads in close proximity. Laser excitation of the donor beads allows for energy transfer by singlet oxygen atoms between the fluorophores.
Incubation with test molecules binding to the bromodomain results in a diminished interaction with the biotinylated substrate leading to a decline in light emission.

Assay format: Thermal Shift

Thermal shift assays measure the thermal stability of a target protein and the increase in protein melting temperature upon the binding of a ligand to the protein. Our thermal shift bromodomain assays are available as service and as a kit for in-house selectivity screening.

Differential Scanning Fluorimetry of BRD2-Tndm (His) in the Presence or Absence of JQ1. Thermal denaturation of BRD2-Tndm (His) was detected by increased binding and fluorescence of the dye SYPRO Orange. Addition of the BET bromodomain inhibitor JQ1 stabilizes the protein folding and shifts the melting temperature from 41 to 44 degrees Celsius.

Assay format: HTRF

HTRF (Homogeneous Time-Resolved Fluorescence) is an assay technology that combines fluorescence resonance energy transfer technology (FRET) with time-resolved measurement (TR) for measuring molecular interactions in a homogeneous format.

HTRF makes use of rare earth complexes such as Europium or Terbium cryptates. These chelates are very stable under a wide range of chemical conditions, are not subject to photobleaching, and show high kinetic stability. HTRF allows enhanced assay performance compared to conventional fluorescent probes in terms of sensitivity, assay window, and robustness.

HTRF assay procedure with a bromodomain: Acetylated peptides are used as substrates for the bromodomains to bind on. Antibodies recognizing the GST tagged-bromodomain are coupled with the donor fluorophore. The peptide is tagged with biotin and recognized by streptavidin which is coupled with an acceptor fluorophore. The proximity of acceptor and donor fluorophore allows for FRET upon excitation.

Incubation with test molecules binding to the bromodomain results in a diminished interaction with the biotinylated substrate leading to a decline in light emission.

Assay setup

Setups: Single-dose screening in duplicates or IC50 value determination with 5 or 10 concentrations. Other screening formats are available upon request.

The thermal shift assay format allows a ‘yes’ or ‘no’ answer whether the test molecule binds to the reader domain protein. IC50 determination is not possible.

Controls: No inhibitor (DMSO vehicle) control and for every assay, one target-specific control compound is tested in 10-dose IC50 format.

Turnaround time: 10 business days for standard projects. Expedited scheduling and data delivery can be arranged prior to the commencement of the studies.

Report: The raw data, % inhibition and control compound IC50 values will be reported in Excel format for single-dose assays. For IC50 orders, raw data, IC50 values, and curve fitting will be delivered in Excel format. Assay conditions, target, and substrate information are available upon request. Requirements for this information should be noted prior to the commencement of the study.

Screening facility: This assay is performed at our screening facility in Malvern, PA, US.

Compound requirements: In brief, for a standard project, 20 µl of a 10 mM DMSO stock or solid material is needed. Less material is needed for large-scale screening. Please refer to our FAQs for information regarding compound preparation and shipping.

Please see our FAQ page to access our assay condition form (US facility).

Monthly screening schedule

On a monthly basis, Reaction Biology performs compound screening on the full bromodomain panel.

Please see the upcoming screening dates here.

Selectivity Profiling

For more information about the selectivity screening of bromodomain proteins visit our BromoMELT^TM Assay Kit page

Cell-based Bromodomain Testing

We offer two assay formats for intracellular compound screening on bromodomain targets:

1. Binding of a compound to BET Bromodomain in intact cells based on NanoBRET Intracellular Target Engagement assay technology.

2. Testing the protein-protein interaction of bromodomains with acetylated histones in intact cells based on the NanoBRET Bromodomain/Histone Interaction Assay.

Please see more information on our Cell-based Epigenetic Assays webpage.