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Single Domain Antibody Discovery Service

Hundreds of alpaca single domain antibody discovery service have been successfully delivered every year. There is a growing number of related research. KMD Bioscience is experienced in the generation of alpaca single domain antibody (sdab) and has been committed to this field for over 9 years. KMD Bioscience has established a comprehensive phage antibody display technology platform. Supported by this phage platform, KMD Bioscience can provide you with high-specificity and high-affinity alpaca single domain antibody production in a short period of time. More time for research, more chance of success.


Single-domain antibodies (sdAbs), also known as nanobodies, are antibody fragments derived from naturally occurring heavy-chain antibodies found in camelids (such as camels, llamas, and alpacas) and cartilaginous fish (such as sharks and rays). Unlike conventional antibodies, which are composed of two heavy chains and two light chains, single domain antibody consist of only one variable domain, usually derived from the heavy chain.


Antibody phage display is a powerful technique used to generate and identify single-domain antibodies, such as VHH antibodies, using bacteriophages as a display platform. The process involves linking the genetic information encoding the VHH antibody to the coat protein gene of a bacteriophage, resulting in the display of the VHH antibody on the surface of the phage particle. KMD Bioscience has an experienced antibody production team and a powerful phage display technology platform to help customers screen for high-quality antibodies.


Alpaca Single Domain Antibody Production Background:


The alpaca is a member of the Camelidae family, which also includes llamas and camels. In addition to conventional IgG, these animals produce a functional single chained antibody that is capable of antigen binding sometimes referred to as VHH single domain antibody. These antibodies consist of only heavy chains and lack the light chains and functional CH1 and CH4 domains. These so-called heavy chain antibody are being used to single domain antibody production. The single domain nature of these antibodies provides unique advantages which set them apart for biotechnological applications.




Fig 1 Schematic representation of the peptide domains for camelid antibodies


Advantages of VHH single domain antibody: (1) The single variable domain of sdAb forms a stable, soluble structure, making them resistant to harsh conditions such as high temperatures, extremes of pH, and protease digestion; (2) VHH single domain antibody can recognize antigenic sites that are normally not recognized by conventional antibodies; (3) their small molecular size helps with rapid tissue penetration and labeling applications including crossing blood-brain barrier; (4) cheaper alternative for large scale production.


Applications of VHH single domain antibody: (1) Targeted Therapy: sdAbs can be engineered to target specific antigens associated with diseases such as cancer, autoimmune disorders, and infectious diseases. They can deliver cytotoxic agents, block receptor-ligand interactions, or modulate immune responses. (2) In Vivo Imaging: labeled with imaging probes such as fluorescent dyes or radionuclides, sdAbs can target and visualize disease-specific biomarkers, aiding in diagnosis, prognosis, and monitoring of therapeutic responses. (3) Drug Delivery: sdAbs can serve as carriers for therapeutic agents, delivering drugs or toxins selectively to disease sites while minimizing off-target effects.


Single Domain Antibody Discovery Service Process:


KMD Bioscience uses the pIII protein of M13 phage for VHH antibody (nanobody) surface display. Our scientists constructed a phage vector with Flag and 6×His tag double tags, and prepared TG1 and XL1-Blue host competent cells with 108 transfection efficiency, after 2-3 transfections and amplification, it can provide customers with a high-quality VHH antibody phage display library with an adequate library capacity of 108-109 and a packaging capacity of 1013-1016/ml. Up to 20-30 high-affinity phage strains can be obtained by three-round nanobody library screening by antigen-limited pressure screening. Through simple IPTG induction, a large number of antibody expression products can be obtained within 1-2 weeks to meet the research needs of customers, such as FACS and cell activity testing.



Single Domain Antibody Production Service Procedure:





Step1: Alpaca Immunization

* A healthy, full-aged Alpaca (28-36 months old) was immunized 4-6 times

* Serum titers were measured by ELISA and collected peripheral blood

8 weeks

Step2: cDNA synthesis (Clients can provide cells)

* Total RNA extraction

* PCR amplification with Actin-specific primers to identify the quality of cDNA

1 day

Step3: VHH single domain antibody Library construction

* Primer design & synthesis

* PCR amplification of variable region genes of heavy using cDNA as a template

* Plasmid construction & transformation: after enzyme digestion, VHH and phagemid vector were ligated and transformed into TG1 host bacteria by an electric shock to construct antibody libraries

* Identification: 20-50 clones were randomly selected, PCR identification, sequencing and analysis of antibody sequences

3-4 weeks

Step4: VHH antibody Library Screening (3 Rounds)

* The antigenic limit pressure method is used for 3 rounds of panning

* Identification: 96 clones were randomly selected for ELISA titer determination

* Up to 96 positive clones were sequenced, and the 10-15 clones were selected for prokaryotic expression transformation

*10-15 positive clones were expressed to construct VHH antibody supernatant

3-4 weeks




--Experimental report: including detailed construction procedures and representative sequence information

--VHH antibody library 2ml, >1⨯1013 /ml phage particles, Effective storage capacity>109

--10-15 positive clones were expressed to prepare VHH antibody supernatant

--10-15 expressing strains of positive clone


Single Domain Antibody Production Service Highlights:


--Provide immune library construction services and natural alpaca antibody library screening services

--Short cycle, high-quality library and monoclonal antibody cell line can be obtained in about 16-20 weeks

--High library capacity: adequate library capacity 108-109/immune library, 109-1011/natural library

--High-affinity antibody construction

--Personalized panning strategy

--Complete document traceability system and QC quality control file


How to Order?

If you have any questions regarding our services or products, please feel free to contact us by E-mail: or Tel: +86-400-621-6806