BioTechniques Publishes Article on Single Domain Antibodies

Many blogs start by asking “Did you know…” to intrigue you to read along. So here it goes:

Did you know that there are more than 300,000 antibodies that are commercially available? And yes, many antibody companies are still generating more antibodies at ever faster pace and in a more systematic way. There are companies that plan to make peptide or short protein fragments for making antibodies against all human proteins or subproteome, others develop antibodies particularly suitable for demanding assays such as ChIP-CHIP. Government activities such as the National Cancer Institute (NCI)’s Clinical Proteomic Technologies Initiative (CPTI) and the Road Map program under the NIH Director’s Office also set goals of producing comprehensive sets of widely usable, renewable, affinity reagents for clinical cancer samples or the human proteome. Apparently people do not think the 300,000 available antibodies are sufficient for what they do.

Did you know that conventional antibodies commonly used as reagents are ~150kDa in molecular weight and can hardly be used inside live cells? Ulrich Rothbauer, professor in the department of biology at Ludwig Maximilians University, who is working with colleagues to develop tools to study cellular processes in living cells. “These antibodies have to assemble four different chains, two heavy and two light, and they’re assembled by disulfide bonds that cannot be correctly formed in the reducing environment of the cytoplasm. You cannot express such a huge complex molecule in living cells. You can [introduce] them by microinjection, for example, but it’s not applicable for high-throughput cell imaging.” [1] Antibody fragments such as scFv, Fab, and similar derivatives have been developed over the years to certain level of success, but not as widely accepted or practically amenable to replacing conventional antibodies.

Did you know that camel, llama, and shark naturally produce single heavy chain antibodies that can function as 13-16kDa fragments (yes if you have read previous Allele Blogs http://allelebiotech.com/blogs/2009/08/camelid-antibodies/)? They can easily be produced in bacteria, used directly inside live cells via transgene, fused to other proteins as a fusion tag, linked to DNA oligos as a detection module, or immobilized on beads for pull down or co-IP. Currently, these antibodies need to be selected by display after obtaining immunized antibody libraries. There is generally no commercial service for creating custom camelid antibodies at this time due to patent and other issues. Existing products are available for jelly fish GFP and DsRed derived RFP fusions. Publications using such a limited number of camelid antibodies have been amazing so far—dozens in top journals within the last few months and after only a short period of time since product launch.

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Original BioTechniques Article http://www.biotechniques.com/news/biotechniquesNews/biotechniques-257771.html?utm_source=BioTechniques+Newsletters+%2526+e-Alerts&utm_campaign=b94f127de0-Methods+Newsletter&utm_medium=email

Tags: Alpaca, camelid antibodies, Chromotek, Fab, GFP-Trap, Hc antibodies, mCherry, mOrange, mPlum, mRFP1, mRuby, nAbs, RFP-Trap, scFv, single domain antibodies, VHH, VHH antibodies

Expanding the Camelid Antibody Product Line

While Chromotek GFP-Trap resin has become one of the best sellers from the Allele Biotech’ Camelid Antibody (VHH antibody) product line, more products have been added that will prove to be great tools for GFP-related research.

GFP is a powerful tool to study protein localization and dynamics in living cells. However, the photo stability and the quantum efficiency of GFP are not sufficient for Super-Resolution Microscopy (e.g. 3D-SIM or STED) of fixed samples from cells expressing GFP-fusion proteins to visualize specific structures. Furthermore, many cell biological methods such as HCl treatment for BrdU-detection, the EdU-Click-iT™ treatment or heat denaturation for FISH lead to disruption of GFP signal.

Now we offer our GFP-Trap Booster for reactivation, boosting and stabilization of GFP, suitable for acquiring strong and long lasting signals from GFP-fusion proteins. It is based on a specific GFP-binding protein as in GFP-Trap but coupled to the fluorescent dye ATTO 488 (from ATTO-TEC). For information, please read the product description of this week New Product of the Week: GFP-Trap booster, ABP-CM-GBOOSTR, http://www.allelebiotech.com/shopcart/index.php?c=221&sc=158

Promotion of the week: All mTFP1 and mWasabi fusion plasmids are 30% off for this week only

Preview of future new product: a similarly high quality product, the RFP-Trap that pulls down DsRed derived proteins including mRFP1, mCherry, mOrange, mPlum but also mRuby and RFP-tagged fusion proteins.

Tags: anti-GFP, Chromotek, GFP coIP, GFP-Trap, mCherry, mOrange, mPlum, mRFP1, mRuby RFP-tagged fusion proteins, nti-RFP, pulldown, RFP-Trap, VHH antibody