Creative Biolabs is one of the well-recognized experts who are professional in high-quality antigen design and preparation. The selection of proper antigen is one of the most critical steps for a successful single domain antibody (sdAb) development project. According to the different targets and expected applications, antigens may need to be designed and prepared in a variety of formats. With over ten years’ extensive experience and advanced antigen preparation platforms, our scientists are confident in designing the best-fit antigens for your project and preparing them in a high-quality manner.
For a typical sdAb development project, we can start with either in silico sequence of the targets or the provided antigens from your side. Based on your project objectives and the target of interest, our scientists are pleased to design and prepare various antigen forms to contribute the further development processes, which including but not limited to:
Soluble Protein as Antigen
Soluble protein (>10 kDa) is one of the most commonly used antigens for sdAb development, which including both recombinant protein and naïve protein. In most cases, soluble proteins can form proper conformation and their complex structure and size also enable to trigger desired immune response.
Our scientists can employ a series of expression systems (e.g. bacterial, mammalian) to generate soluble proteins with desired properties and conjugations, which can be used as qualified antigens for sdAb development.
Peptide as Antigen
As a viable alternative to protein antigens, the peptide antigens present great potentials for antibodies generation. In general, the most common and optimal peptide length for antibody production is around 8-25 residues. With the conjugation of carrier proteins (e.g. KLH, biotin, BSA), such peptides can function as immunogens for sdAb development. Virtually, peptides with appropriate post-translational modification have been employed as antigens for almost all PTM-specific antibody development projects.
Our scientists can offer the intact peptide antigen preparation based on the provided in silico sequence. Or we can provide custom conjugation services to the provided peptides.
Hapten as Antigen
Hapten antigens are small molecules that are antigenic (can be recognized by specific antibodies) but not immunogenic. The “free” hapten cannot elicit immune responses until it is combined with larger carriers (e.g. protein). Some typical haptens including aniline, urushiol, hydralazine, and digoxigenin.
Specific sdAb against a hapten can only be raised through properly designed hapten-carrier conjugation and adjuvant. Our scientists have extensive experience in handling such projects and are pleased to tailor the best-fit proposal for hapten antigen preparation.
Intact Membrane Protein as Antigen
Membrane proteins (such as ion channels, receptors, and transporters) play a critical role in multiple biological processes and also represent a large number of drug targets. While, because of their low natural abundance and highly complicated structure, the preparation of intact membrane proteins without great influence on their conformation is still a big challenge.
Creative Biolabs has established a powerful platform for membrane protein generation. In terms of multiple cutting-edge technologies, our scientists can generate high-quality membrane proteins as qualified antigens for sdAb development.
Whole Cell as Antigen
Cell line overexpressing the target of interest can also be employed as antigen for sdAb development. In this case, another cell line from the same host strain but does not express the target is required as a negative control. Whole cell antigen can benefit from naïve antigen formation, higher immunogenicity and also avoid complex purification process of the target (extracellular domain), which is an alternative option for the development of anti-membrane protein sdAbs.
Our scientists can culture the provided cell lines with your specific protocol or provide comprehensive cell line construction service for your project.
DNA as Antigen
For antigens which are difficult to be expressed or purified, DNA immunization would be a wonderful choice to permit in vivo antigen production and trigger the desired immune response. This approach can maximally maintain the naïve conformation of targets and also some post-transcriptional modifications.
Based on the provided in silico sequence, our scientists can construct DNA plasmid encoding the target as an antigen or take the advantages of our unique Magic™ platform to enhance the transfection efficiency and induce a robust immune response. We can also start with the provided DNA plasmid.
Custom Camelid Fc-Fusion Protein Preparation as Immunogen
In order to overcome difficult problems such as small antigens and tag immunogenicity, our scientists with extensive experience could provide a unique series of camelid (e.g., llama, alpaca, camel) Fc-fusion proteins for immunogen preparation to obtain a promising immune response against targets in the immunization stage. These camelid Fc-fusion proteins have a series of advantages to be used as immunogens, including enhanced target immunogenicity, much lower tag immunogenicity, and high purity and activity.
As a leading custom service provider in the field of antigen preparation, Creative Biolabs has successfully accomplished numerous challenging antigen preparation projects. If you are interested in our services, please do not hesitate to contact us for more details.
