DASS (Database Assisted Shotgun Sequencing) Technology

Based on our proprietary DASS (Database Assisted Shotgun Sequencing) technology platform, Creative Biolabs has accumulated a large number of successful cases over the years to provide clients with 100% accurate de novo antibody sequencing services.

DASS Principle

Proteolytically cleaved peptide molecules show regular breaks in mass spectrometry. Specific breakage patterns are identified, and the corresponding amino acid information and post-translational modifications on the amino acids can be figured out from the mass difference between the mass spectral peaks using our "in-house" data mining algorithm.

DASS-based sequencing workflow. (Creative Biolabs original)

Features of DASS Technology

1Full Sequence Coverage

  • Multiple cleavages are performed to achieve full sequence splicing of the antibody by recognizing the complementarity between different cleaved peptides.
  • The CDR sequence in the core region of the antibody is covered more repeatedly to fully ensure sequencing accuracy.

2Discrimination of Leucine & Isoleucine

  • Side-chain fragmentation of leucine and isoleucine can be produced using ETD fragmentation for MS2 fragmentation of peptides and HCD fragmentation to generate MS3 for targeted z-ions.
  • Precise discrimination of Leu/Ile can accelerate your project schedule by avoiding trying the expression of different variants, which also saves you money.

3Confirmation of Hypermutations

  • Using a high error-tolerant mapping technique, it is possible to identify hypermutations brought on by the B cell maturation process and accurately link "mutated" peptides to the relevant germline.
  • Sequence information for EVERY peptide bond in the antibody could be obtained. Each amino acid (AA) location typically generates 20-70 distinct MS/MS spectra. We guarantee >5x for the complete VDJ sequence.

4Compatible with All Antibody Formats

  • Our DASS technology works with all antibody formats from all species (mouse, rat, hamster, llama, rabbit, etc.; Fab, scFv, etc.).
  • Some mAbs are coupled to matrices, which our sequencing method can handle but might necessitate larger sample sizes.
  • Our method is typically robust against small ligands (e.g., FITC, Biotin, Fluorescent dyes) linked to antibodies, and can overcome the sequencing challenge of larger protein ligands (e.g., PE, APC).

5High Quality Spectra

  • Our state-of-the-art mass spectrometer allows all three common fragmentation techniques as CID (Collision-Induced Dissociation), HCD (Higher-energy Collisional Dissociation), and ETD (Electron Transfer Dissociation), which ensures that any sequence can be solved with the highest accuracy.
  • We further optimized the collision conditions (type of gas, pressure, and energy input) in order to maximize the completeness of the y- and b-ion series.

Applications

Confirmation and validation of manufacturing

Obtaining sequences of antibodies, proteins, and enzymes facilitates the identification and control of manufacturing lot-to-lot variation issues.

IND (Investigational New Drug) /NDA (New Drug Application) application

Sequencing to obtain accurate primary structure information to serve as the basis for antibody drug development.

Antibody engineering

Obtaining antibody sequences for various forms of recombinant antibody expression, as well as for antibody humanization.

Creative Biolabs provides de novo sequencing and analysis services for extensive types of antibodies based on DASS technology, establishing a one-stop platform for antibody development services. Our DASS technology is proven to be a reliable tool for the discovery of novel therapeutic antibodies, as well as for the development of generic or biosimilar antibody drugs. Our custom services include but are not limited to antibody designing, cloning, production, and in vitro optimization to fulfill your needs. Please contact us to acquire a customized solution.

For Research Use Only | Not For Clinical Use

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