RFP-Trap Magnetic Agarose


The ChromoTek RFP-Trap® Magnetic Agarose are affinity beads for immunoprecipitation of RFP-fusion proteins.
It comprises a RFP Nanobody/ VHH coupled to magnetic agarose.

mCherry, mRFP, mPlum, tagRFP, mKate2 and more RFP derivatives:
Fluorescent protein specificity table

Immunoprecipitation/ Co-IP
Mass spectrometry
On-bead enzyme assays
ChIP/ RIP analysis

Product Size Code Price Buy
Product RFP-Trap Magnetic Agarose Size 250 µL (10 reactions) Code rtma-10 Price $ 275
Buy +
Product RFP-Trap Magnetic Agarose Size 500 µL (20 reactions) Code rtma-20 Price $ 475
Buy +
Product RFP-Trap Magnetic Agarose Size 2.5 mL (100 reactions) Code rtma-100 Price $ 2050
Buy +
Product RFP-Trap Magnetic Agarose Size 5 mL (200 reactions) Code rtma-200 Price Please inquire
Product RFP-Trap Magnetic Agarose Size 10 mL (400 reactions) Code rtma-400 Price Please inquire
Product RFP-Trap Magnetic Agarose Kit Size 500 µL (20 reactions) Code rtmak-20 Price $ 595
Buy +
Product Binding Control Magnetic Agarose Beads Size 500 µL (20 reactions) Code bmab-20 Price $ 75
Buy +
Product RFP VHH, recombinant binding protein Size 250 µL Code rt-250 Price $ 275
Buy +

Dissociation constant KD of 5 nM

Wash buffer compatibility
4 M urea, 2 M NaCl, 10 mM DTT, 2 % Nonidet P40 Substitute, 1 % Triton X-100

Specificity (selection)
mRFP, mCherry, mRFPruby, mPlum, tagRFP, mKate2, mOrange, PA-mCherry, mScarlet and more.
For complete list, please click here: Fluorescent protein specificity table

Binding capacity
10 µL slurry bind ~8 µg of recombinant mCherry

Coupled Nanobody/ VHH
recombinant, monoclonal anti-Red Fluorescent Protein (RFP) single domain antibody (sdAb) fragment

Bead properties
Bead size: ~ 40 µm
Storage buffer: 20 % EtOH

- SDS sample buffer
- 0.2 M glycine pH 2.5
Instead of elution, we recommend on-bead assays like on-bead digestion for MS analysis.

Compatibility with mass spectrometry
The RFP-Trap is optimized for on-bead digestion. Complete tryptic digest results in 6-7 peptides.

How to cite this product
RRID: AB_2631363

Storage instructions
Shipped at ambient temperature. Upon receipt store at 4°C. Stable for one year.

Rose Willett,Jose A Martina,James P Zewe,Rachel Wills,Gerald R V Hammond,Rosa Puertollano (2017), TFEB regulates lysosomal positioning by modulating TMEM55B expression and JIP4 recruitment to lysosomes., Nat Communlink
Anne Ramat,Matthew Hannaford,Jens Januschke (2017), Maintenance of Miranda Localization in Drosophila Neuroblasts Involves Interaction with the Cognate mRNA., Curr Biollink
Marie Maclennan,Marta Garcia-Cañadas,Judith Reichmann,Elena Khazina,Gabriele Wagner,Christopher J Playfoot,Carmen Salvador-Palomeque,Abigail R Mann,Paula Peressini,Laura Sanchez,Karen Dobie,David Read,Chao-Chun Hung,Ragnhild Eskeland,Richard R Meehan,Ol. (2017), Mobilization of LINE-1 retrotransposons is restricted by Tex19.1 in mouse embryonic stem cells., Elifelink
Nagendra Babu Thillaiappan,Alap P Chavda,Stephen C Tovey,David L Prole,Colin W Taylor (2017), Ca2+signals initiate at immobile IP3receptors adjacent to ER-plasma membrane junctions., Nat Communlink
Wei Jiang,Yuehua Wei,Yong Long,Arthur Owen,Bingying Wang,Xuebing Wu,Shuo Luo,Yongjun Dang,Dengke K Ma (2018), A genetic program mediates cold-warming response and promotes stress-induced phenoptosis in C. elegans., Elife, link
Hui Li,Nan Luo,Weidong Wang,Zengyu Liu,Jisheng Chen,Liangtao Zhao,Li Tan,Chunyan Wang,Yuan Qin,Chao Li,Tongda Xu,Zhenbiao Yang (2018), The REN4 rheostat dynamically coordinates the apical and lateral domains of Arabidopsis pollen tubes., Nat Communlink
Sheng Sun,Vikas Yadav,R Blake Billmyre,Christina A Cuomo,Minou Nowrousian,Liuyang Wang,Jean-Luc Souciet,Teun Boekhout,Betina Porcel,Patrick Wincker,Joshua A Granek,Kaustuv Sanyal,Joseph Heitman (2017), Fungal genome and mating system transitions facilitated by chromosomal translocations involving intercentromeric recombination., PLoS Biollink

What are the biophysical parameters of the RFP-Trap®?

Molecular weight: 14,9 kDa; Extinction coefficient: 30035 M-1 cm-1

Should I use an N-terminal or C-terminal fusion tag?

Both the N-terminal or C-terminal fusion tag work well with the traps.

How can I avoid unspecific protein interactions binding to the trap?

For preclearing of your sample we recommend to use our binding controls (bab-20 or bmab-20).

Please find more information in our Troubleshooting guide

How can I elute bound proteins from a trap in their native state?

You can elute your fusion protein of interest with 0.2 M glycine pH 2.5 at room temperature. Pipette the beads up and down for 60-120 seconds and repeat this step. Ensure to neutralize your supernatant immediately afterwards by adding 1 M Tris base pH 10.4.

How many mammalian cells are required for an immunoprecipitation reaction?

For one immunoprecipitation reaction, we recommend using ~10^6 - 10^7 mammalian cells. The yield is also dependent on the expression level of your protein of interest and the interaction partners.

How much cell extract should I use for an immunoprecipitation reaction?

For other type of cells than mammalian cells, we recommend using 0.5 - 1.0 mg of cell extract.

Do I need to elute bound proteins from the beads for mass spectrometry analysis?

No, you can directly conduct an on-bead digestion after immunoprecipitation. This procedure allows faster and more efficient sample preparation and a potential higher yield.
Please find more information here:

Preomics kit

Protocol on-bead digestion

Do I need to elute my protein of interest from the beads for enzymatic assays?

No, you can directly perform your enzymatic assay on the beads if the active center is not blocked.

Please find more information in our application note "enzymatic activity assay"

What is the amount of trap slurry I need for one immunoprecipitation reaction?

25 µL slurry are sufficient for one pull-down reaction as the affinity of the traps is very high.

Specifications of RFP-Trap Agarose, Magnetic Agarose, and Magnetic Beads





Magnetic Agarose

Magnetic Beads


Agarose (4% cross-linked)

Magnetic agarose (6% cross linked)

Magnetic Beads M-270

Bead form


Porous; sold iron core






RFP-tagged protein size*

Small to large size

Small to large size

Small to very large size; no size limitation





Medium particle size

90 µm

40 µm

2.8 µm

Binding capacity

9 µg/ 10 µL

8 µg/ 10 µL

0.5 μg/ 10 μL


Very low



Magnetic separation & automation




May be centrifuged up to

2,500 x g

800 x g

8,000 x g

* Does depend on protein size and shape, protein multimers, complexes and interaction partners


  • From cell to gel in less than one hour
  • No heavy & light chains in your downstream application
  • Robust performance with high yield
  • Short incubation time of about 30 minutes

RFP-Trap Magnetic Agarose Kit

The RFP-Trap Magnetic Agarose is also available in a kit, including:

  • RFP-Trap Magnetic Agarose
  • Lysis*, wash and elution buffers

*The lysis buffer provided is suitable for mammalian cells. For other cell types use another suitable lysis buffer.

Binding Control for Magnetic Agarose Beads


"...the beads were glowing purple so we knew there was a ton of mCherry on them! I think the RFP-Trap is a really nice reagent..."
Prof. Dr. Laura Trinkle-Mulcahy, University of Ottawa
"We have found your trap tools extremely useful, the purification effect is way superior to most of our antibodies. This tool proved very helpful in our research and we are practically addicted on it."
Dr. Ondrej Plihal, Institute of Microbiology, Department of Ecology
"I am a big fan of all GFP/RFP-Trap for Co-IP experiments and we use it regularly. Same thing for the labeled antigen specific nano-bodies."
Dr. Harald Wodrich, University Bordeaux

Download Whitepaper
Order Free Test-Sample
Email newsletter

Only for research applications, not for diagnostic or therapeutic use!