VHH antibodies (also known as nanobodies, single domain antibodies, or sdAbs) have been used in diagnostics, especially imaging, therapeutics (therapeutic antibodies, bispecific antibodies, CAR T, and ADCs), manufacturing, and research reagents. VHH antibodies differ from other conventional antibody formats in their unique size characteristics, intrinsic stability, solubility, easy tailoring into pluripotent constructs, recognition of rare or concealed epitopes, the ease and speed of drug discovery, and the ease of manufacture.
Alpha Lifetech Inc. is recognized as a leader in single-domain antibody discovery. Alpha Lifetech Inc. has developed proprietary procedures for nanobody discovery. Our optimized library construction and screening processes with phage display technology ensure the successful isolation of high-affinity alpaca nano-bodies within a short period of time. We have succeeded in producing multiple positive clones for a variety of antigens, ranging from large protein molecules to small haptens, many binding agents have subnanomolar affinities measured by ELISA.
Alpaca VHH Antibody Library Discovery Service Background
In addition to conventional IgG, Alpaca produces a single-chain functional antibody which is capable of antigen binding sometimes called VHH antibodies. These antibodies consist solely of heavy chains and lack lightweight chains and functional domains CH1 and CH4. These so-called heavy-chain antibodies are used in the development of single-domain antibodies.
The single domain nature of these antibodies provides unique advantages that sets them apart for biotechnology applications. Some of these advantages include,
a) Stability at high temperatures & pH.
b) VHHs can recognize antigenic sites that are normally not recognized by conventional antibodies.
c) Their small molecular size helps with rapid tissue penetration and labeling applications, including crossing the blood-brain barrier.
d) Less expensive for large-scale production.
Alpaca VHH Antibody Library Discovery Service
Alpaca VHH Antibody Library Discovery Service Details
|
Steps |
Specification |
Timeline |
|
Step1: Alpaca Immunization |
--Earthy, full-aged Alpaca (28-36 months old) was immunized 4-7 times
--Serum titers were measured by ELISA and collected peripheral blood |
6-8 weeks |
|
Step2: cDNA synthesis (Clients can provide cells) |
--Total RNA extraction
--RT-PCR
--PCR amplification with Actin-specific primers to identify the quality of cDNA |
1 day |
|
Step3: VHH 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 |
|
VHH-Fc Antibody Production (optional) |
--Gene synthesis, subcloning, plasmid preparation
--Transient expression and purification
--QC analysis |
2 weeks |
|
Affinity Ranking (optional) |
--Affinity measured by Biacore 8K |
1 weeks |
Deliverables
--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
Service Features of Alpaca VHH Antibody Library Discovery Service
--Provide immune library construction services and natural alpaca antibody library screening services
--A high-quality library and monoclonal antibody cell line can be obtained in approximately 16-20 weeks
--High library capacity: adequate library capacity 108-109/immune library, 109-1011/natural library
--Constructing high affinity antibodies
--Personalized panning strategy
--Complete document traceability system and QC quality control file
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