BAC looks to enhance laboratory purification with new antibody toolkit

Bio Affinity Company (BAC) has launched a new antibody purification toolbox based on its successful industrial-scale technology to provide researchers with a simpler purification route.

Antibodies are used in many different areas of drug discovery and life science research, from being used to isolate proteins that may be drug targets to being studied as therapeutics in their own right.

They are commonly purified using one of three proteins, Protein A, G or L, which have different antibody binding profiles that enable researchers to pluck out different types of antibodies from biological mixtures by judicial selection.

The new CaptureSelect antibody toolkit currently consists of four products that have been designed to bind specific antibody domains that enable easy purification by eliminating many of the drawbacks associated with the current 'gold-standards'.

"We saw a need for a new product for antibody purification in the lab. Currently, researchers using Proteins A, G or L face a number of obstacles in the design and optimisation of a protocol for their specific antibody," said Mark ten Haaft, director of Ligand Application at BAC.

"The Antibody Toolbox takes away the uncertainty involved in selecting the appropriate affinity media for the job, and minimises method testing and optimisation."

One of the major drawbacks of using traditional affinity purification methods is that elution of the bound antibodies can be problematic due to the acidic conditions that need to be used.

"The real advantage of the CaptureSelect toolkit is that they are designed to elute the products nicely, a part of the process that can cause problems if you are using Protein A, L and G as this step requires low pHs," said Laurens Sierkstra, CEO of BAC.

While the Dutch company's industrial scale products have met with considerable success and have been licensed to a variety of distributors, most notably GE Healthcare , the launch of this new product range is the first time the company has directly sold products to laboratory researchers.

"Until now we have offered our ligands for large scale industrial use only, and the Antibody Toolbox is our first off-the-shelf product range that will be sold direct to the lab researcher," said Sierkstra.

"This launch marks a strategic shift for us that aims to get the company more widely known to the end user."

The first part of this process was to make the products available through BAC's website , but Sierkstra said the company was in discussion with various distributors about the possibilities of widening the product's availability and visibility, as well as potentially repackaging the media in different formats.

The toolbox consists of affinity matrices for purifying human antibodies containing kappa light chains, lambda light chains, an Fc matrix for purifying all subclasses of human IgG (immunoglobulin G) and one for purifying IgG from multiple species.

According to Sierkstra, the company will be looking to add to range in the new year with the launch of affinity purification media for IgA and IgM antibodies that will not bind to IgG.

The products are produced using BAC's ligand generation technology that is based on the unique single chain antibodies found in Camelids (llama and camels) and manufactured in Saccharomyces cerevisiae (S. cerevisiae) host cells.

The ligands are small, single domain fragments of these antibodies that comprises of the three "complementarity determining regions" or CDRs that are involved in antigen binding.

They are particularly stable and show high affinity and selectivity, providing competitive benefits in terms of reducing the cost of purification, increased purification process flexibility and higher product purity.

The specificity of the ligands can be tuned such that they can either purify a broad range of antibodies from a species or a very narrow range such as certain antibody glycoforms, isomers of idiotypes.

"The selection process specifically screens for ligands that bind to specific epitopes that are not present in other molecules, such that the Protein A replacement it only binds to the human IgG and not antibodies from other species," said Sierkstra.