{ "id": "ep2agtfcef", "slug": "bioconjugation", "title": "Bioconjugation", "updated": "2026-10-15", "topic_path": [ { "id": "physical", "label": "Physical world and mathematics", "api_url": "https://www.edgepedia.org/api/v1/topics/physical" }, { "id": "physical.chemistry", "label": "Chemistry", "api_url": "https://www.edgepedia.org/api/v1/topics/physical.chemistry" }, { "id": "physical.chemistry.methods", "label": "Chemical principles and methods", "api_url": "https://www.edgepedia.org/api/v1/topics/physical.chemistry.methods" }, { "id": "physical.chemistry.methods.chemical-synthesis", "label": "Chemical synthesis", "api_url": "https://www.edgepedia.org/api/v1/topics/physical.chemistry.methods.chemical-synthesis" } ], "geo": [ { "id": "geo.nongeo.t1800.physical.chemistry.methods.chemical-synthesis", "label": "Non-geographic · 1800 to 1945: Chemical synthesis", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1800.physical.chemistry.methods.chemical-synthesis", "path": [ { "id": "geo.nongeo", "label": "Non-geographic", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo" }, { "id": "geo.nongeo.t1800", "label": "Non-geographic · 1800 to 1945", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1800" }, { "id": "geo.nongeo.t1800.physical", "label": "Physical world and mathematics", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1800.physical" }, { "id": "geo.nongeo.t1800.physical.chemistry", "label": "Chemistry", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1800.physical.chemistry" }, { "id": "geo.nongeo.t1800.physical.chemistry.methods", "label": "Chemical principles and methods", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1800.physical.chemistry.methods" }, { "id": "geo.nongeo.t1800.physical.chemistry.methods.chemical-synthesis", "label": "Chemical synthesis", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1800.physical.chemistry.methods.chemical-synthesis" } ] }, { "id": "geo.nongeo.t1946.physical.chemistry.methods.chemical-synthesis", "label": "Non-geographic · 1946 to 2000: Chemical synthesis", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.physical.chemistry.methods.chemical-synthesis", "path": [ { "id": "geo.nongeo", "label": "Non-geographic", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo" }, { "id": "geo.nongeo.t1946", "label": "Non-geographic · 1946 to 2000", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946" }, { "id": "geo.nongeo.t1946.physical", "label": "Physical world and mathematics", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.physical" }, { "id": "geo.nongeo.t1946.physical.chemistry", "label": "Chemistry", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.physical.chemistry" }, { "id": "geo.nongeo.t1946.physical.chemistry.methods", "label": "Chemical principles and methods", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.physical.chemistry.methods" }, { "id": "geo.nongeo.t1946.physical.chemistry.methods.chemical-synthesis", "label": "Chemical synthesis", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.nongeo.t1946.physical.chemistry.methods.chemical-synthesis" } ] } ], "excerpt": "Bioconjugation is the chemical joining of molecules by a covalent bond in which at least one partner is a biomolecule, producing antibody–drug conjugates, fluorescent probes, and biotinylated proteins.", "snippet": "Bioconjugation is the chemical joining of molecules by a covalent bond in which at least one partner is a biomolecule, producing antibody–drug conjugates, fluorescent probes, and biotinylated proteins.", "node": "physical.chemistry.methods.chemical-synthesis", "markdown": "# Bioconjugation\n\nBioconjugation is the chemical joining of two or more molecules by a covalent bond in which at least one partner is a biomolecule.[1](https://assets.thermofisher.com/TFS-Assets/BID/Handbooks/bioconjugation-technical-handbook.pdf) Typical products include biotinylated proteins, fluorescent antibody probes, immobilized biomolecules, metabolically labeled glycans, and antibody–drug conjugates (ADCs).[1](https://assets.thermofisher.com/TFS-Assets/BID/Handbooks/bioconjugation-technical-handbook.pdf) Reviews frame the field as mild, often site-specific derivatization of proteins, DNA, RNA, and carbohydrates for ligand discovery, disease diagnosis, and high-throughput screening.[2](https://europepmc.org/article/pmc/2901115)\n\n| Key fact | Value |\n|---|---|\n| Definition | Covalent linkage where at least one partner is a biomolecule[1](https://assets.thermofisher.com/TFS-Assets/BID/Handbooks/bioconjugation-technical-handbook.pdf) |\n| NHS ester coupling | pH 7.2–8.5, phosphate/carbonate/HEPES/borate, 30 min–4 h; Tris incompatible[1](https://assets.thermofisher.com/TFS-Assets/BID/Handbooks/bioconjugation-technical-handbook.pdf) |\n| Maleimide–thiol kinetics | \\( k_{2} \\) = 100–1000 M⁻¹ s⁻¹, optimal pH 6.5–7.5[3](https://royalsocietypublishing.org/rsos/article-pdf/doi/10.1098/rsos.211563/994493/rsos.211563.pdf) |\n| NHS ester hydrolysis | Half-life 4–5 h at pH 7 (4 °C), 1 h at pH 8, 10 min at pH 8.6[4](https://www.mdpi.com/1420-3049/28/3/1083) |\n| Stochastic conjugation | DAR 0–9; six payloads on an IgG give ≈120 million regioisomers[5](https://link.springer.com/article/10.1007/s11095-014-1596-8) • [3](https://royalsocietypublishing.org/rsos/article-pdf/doi/10.1098/rsos.211563/994493/rsos.211563.pdf) |\n| Approved ADCs | 19 worldwide as of July 2025[6](https://link.springer.com/article/10.1208/s12249-026-03445-z) |\n| In vivo TCO–tetrazine ligation | \\( k_{2} \\) > 100,000 M⁻¹ s⁻¹[7](https://www.nature.com/articles/s41586-026-10789-w) |\n\n## How it works\n\nConjugation targets the most nucleophilic groups on a protein under near-physiological conditions. Lysine conjugation uses the solvent-accessible ε-amines, given as approximately 40 on a standard IgG1.[8](https://academic.oup.com/abt/article/8/2/157/8115463?searchresult=1) NHS esters acylate lysine by acyl transfer with displacement of N-hydroxysuccinimide (pKa 6.0), but they also react with cysteine, serine, tyrosine, and threonine, so chemo- and regioselectivity are poor.[9](https://pubs.rsc.org/en/content/articlepdf/2021/sc/d1sc02973h) The resulting amide bond is very stable; one review estimates a half-life up to 600 years in neutral water.[3](https://royalsocietypublishing.org/rsos/article-pdf/doi/10.1098/rsos.211563/994493/rsos.211563.pdf)\n\nCysteine is the selectivity workhorse: its thiol (pKa ≈ 8) is more acidic than the lysine amine (pKa ≈ 10) and, as a soft nucleophile, reacts selectively with soft Michael acceptors such as maleimides.[9](https://pubs.rsc.org/en/content/articlepdf/2021/sc/d1sc02973h) Maleimides add thiolates by thio-Michael reaction with \\( k_{2} \\) of 100–1000 M⁻¹ s⁻¹; cysteine's low abundance (about 1.5% of residues) and thiol pKa of 8.8–9.1 make it a convenient target.[3](https://royalsocietypublishing.org/rsos/article-pdf/doi/10.1098/rsos.211563/994493/rsos.211563.pdf) For targets absent from proteins, bioorthogonal chemistry uses two steps: first incorporate a handle such as an azide, then add an exogenous probe such as an alkyne that reacts rapidly and selectively.[10](https://pubs.acs.org/doi/full/10.1021/acs.bioconjchem.1c00461) Azide–alkyne and azide–phosphine pairs are foreign to biological systems; the strain-promoted variant proceeds without copper, avoiding copper-induced damage to GFP.[1](https://assets.thermofisher.com/TFS-Assets/BID/Handbooks/bioconjugation-technical-handbook.pdf)\n\n## How it is done\n\n**NHS ester coupling.** Run reactions in phosphate, carbonate–bicarbonate, HEPES, or borate buffer at pH 7.2–8.5 for 30 min to 4 h at room temperature or 4 °C; primary-amine buffers such as Tris compete for the reagent and are excluded.[1](https://assets.thermofisher.com/TFS-Assets/BID/Handbooks/bioconjugation-technical-handbook.pdf) [Hydrolysis](https://www.edgepedia.org/hydrolysis) competes throughout: the half-life is 4–5 h at pH 7 and 4 °C, 1 h at pH 8, and 10 min at pH 8.6.[4](https://www.mdpi.com/1420-3049/28/3/1083)\n\n**Maleimide–thiol ligation.** Reduce disulfides (TCEP in published protocols), then react at pH 6.5–7.5 to form a thioether; above pH 8.5 primary amines and maleimide hydrolysis compete.[1](https://assets.thermofisher.com/TFS-Assets/BID/Handbooks/bioconjugation-technical-handbook.pdf) The most widely used heterobifunctional crosslinkers pair an NHS ester with a maleimide, adding the NHS ester first because it is less stable in water.[1](https://assets.thermofisher.com/TFS-Assets/BID/Handbooks/bioconjugation-technical-handbook.pdf) At manufacturing scale, brentuximab vedotin is made by reacting 6 equivalents of maleimide linker-payload with the antibody within 1 h in DMSO (11% v/v) and pH 7.0 buffer, giving 85–88% yield at average DAR 3.6.[9](https://pubs.rsc.org/en/content/articlepdf/2021/sc/d1sc02973h)\n\n**CuAAC.** Use sodium ascorbate, 50–100 μM Cu, at least 5 equivalents of THPTA ligand per Cu, and aminoguanidine in phosphate, carbonate, or HEPES at pH 6.5–8.0; Tris is avoided as a competitive Cu ligand.[10](https://pubs.acs.org/doi/full/10.1021/acs.bioconjchem.1c00461)\n\n## Origin\n\nHunter and Ludwig reported the reaction of imidoesters with proteins in 1962 in the [Journal of the American Chemical Society](https://www.edgepedia.org/journal-of-the-american-chemical-society).[11](https://doi.org/10.1021/ja00877a016) Means and Feeney's 1990 account of chemical protein modification consolidated the field's history and applications in Bioconjugate Chemistry.[12](https://doi.org/10.1021/bc00001a001) Kalia and Raines's 2010 review in Current Organic Chemistry systematized chemoselective reactions for physiological conditions and, unusually, treated linkage stability as a central topic.[2](https://europepmc.org/article/pmc/2901115) The Staudinger ligation, with kinetics near \\( 10^{-3} \\ \\mathrm{M^{-1} \\cdot s^{-1}} \\), was the pioneering bioorthogonal conjugation and was progressively displaced by CuAAC (\\( k_{2} \\) 10–100 \\( \\mathrm{M^{-1} \\cdot s^{-1}} \\)).[3](https://royalsocietypublishing.org/rsos/article-pdf/doi/10.1098/rsos.211563/994493/rsos.211563.pdf) [Click chemistry](https://www.edgepedia.org/click-chemistry) and bioorthogonal chemistry were awarded the [Nobel Prize in Chemistry](https://www.edgepedia.org/nobel-prize-in-chemistry) 2022.[4](https://www.mdpi.com/1420-3049/28/3/1083)\n\n## Variants\n\nBioorthogonal ligations must typically run below 37 °C, in aqueous media at near-neutral pH, and reach full conversion within minutes to hours at low substrate concentration.[13](https://pmc.ncbi.nlm.nih.gov/articles/PMC10665463/) The Staudinger ligation gives stable amides but is slow and its phosphines oxidize; CuAAC is fast and regioselective but copper toxicity is a concern; SPAAC avoids copper but is slower with bulky cyclooctynes; tetrazine ligation is very fast with tunable kinetics but the tetrazine is less stable in water.[10](https://pubs.acs.org/doi/full/10.1021/acs.bioconjchem.1c00461) Site-selective options span several orders of magnitude: the π-clamp (Phe-Cys-Pro-Phe) perfluoroarylates cysteine at 0.76 M⁻¹ s⁻¹ (pH 8, 37 °C), tetrazine–thiol exchange runs at 1–100 M⁻¹ s⁻¹ at pH 7.4, and 2-formylphenylboronic acid forms thiazolidino boronates at \\( 10^{3} \\ \\mathrm{M^{-1}\\cdot s^{-1}} \\).[13](https://pmc.ncbi.nlm.nih.gov/articles/PMC10665463/) • [14](https://www.beilstein-journals.org/bjoc/articles/22/67) At the top of the range, antibody–TCO and ADC–tetrazine conjugates ligate in vivo with \\( k_{2} \\) > 100,000 M⁻¹ s⁻¹.[7](https://www.nature.com/articles/s41586-026-10789-w)\n\nNonspecific lysine or cysteine modification yields heterogeneous mixtures that cannot be further purified, whereas site-specific conjugation gives more homogeneous products with demonstrated in vivo benefits.[15](https://pmc.ncbi.nlm.nih.gov/articles/PMC4335810/) The PHESELECTOR phage ELISA identified heavy-chain alanine 114 (Kabat) as the optimal cysteine substitution site, giving rise to the THIOMAB platform, an approach of attaching payloads to introduced surface cysteines.[5](https://link.springer.com/article/10.1007/s11095-014-1596-8) • [16](https://doi.org/10.1093/protein/3.8.703) **Disulfide rebridging** replaces reduced interchain disulfides with a bridging linker; next-generation maleimides, introduced by Schumacher, Nunes, and colleagues in 2014 in Organic & Biomolecular Chemistry, achieved complete rebridging of reduced trastuzumab with 5 equivalents of dibromomaleimide or dithiophenolmaleimide in under 1 h, yielding DAR 4, 8, or 16 without altering the genetic code or glycosylation.[17](https://doi.org/10.1039/c4ob01550a) • [18](https://pubs.rsc.org/en/content/articlehtml/2021/cs/d0cs00310g) **Glycan remodeling** targets the conserved Fc glycan at N297: glycans are trimmed with an endoglycosidase, an azido-galactose is added with a galactosyltransferase, and the payload is attached by click chemistry; well-defined ADCs through this route and SPAAC were demonstrated by Li, Fang, and Boons in 2014.[8](https://academic.oup.com/abt/article/8/2/157/8115463?searchresult=1) • [19](https://doi.org/10.1002/anie.201402606) **Unnatural amino acids** are incorporated at a pre-mutated TAG stop codon using a host-orthogonal aminoacyl-tRNA synthetase/tRNA pair.[8](https://academic.oup.com/abt/article/8/2/157/8115463?searchresult=1) • [20](https://doi.org/10.1073/pnas.1211023109) **Enzymatic ligation** includes sortase-mediated [protein ligation](https://www.edgepedia.org/protein-ligation), reported as a new protein engineering method by Mao, Hart, Schink, and Pollok in 2004 in the Journal of the American Chemical Society; sortagging is limited to the [C-terminus](https://www.edgepedia.org/c-terminus), has slow kinetics, and needs a large (~10:1) nucleophile excess.[21](https://doi.org/10.1021/ja039915e) • [5](https://link.springer.com/article/10.1007/s11095-014-1596-8) Bacterial transglutaminase modifies antibodies site-specifically and stoichiometrically, as shown by Jeger, Zimmermann, and colleagues in 2010 in Angewandte Chemie International Edition.[22](https://doi.org/10.1002/anie.201004243)\n\n## Applications\n\nADCs are the flagship application. At the time of a 2021 review, nine ADCs had FDA approval and more than 80 others were in clinical investigation; all nine were made by lysine or cysteine modification, and in approved ADCs the conjugation chemistry is limited to NHS ester and maleimide kinds.[18](https://pubs.rsc.org/en/content/articlehtml/2021/cs/d0cs00310g) • [9](https://pubs.rsc.org/en/content/articlepdf/2021/sc/d1sc02973h) As of June 30, 2026, 23 ADCs have received regulatory approval worldwide (including products later withdrawn), most using cleavable peptide linkers, with over 150 clinical candidates.[6](https://link.springer.com/article/10.1208/s12249-026-03445-z) Beyond oncology, the same chemistries serve biotinylation, dye conjugation, immobilization, metabolic labeling, and structural studies.[1](https://assets.thermofisher.com/TFS-Assets/BID/Handbooks/bioconjugation-technical-handbook.pdf) [In vivo](https://www.edgepedia.org/in-vivo) click assembly is a newer direction: FDA-approved antibodies and ADCs administered sequentially ligate in tumors via inverse electron-demand Diels–Alder chemistry, improving antitumour activity over ADC monotherapy in HER2/EGFR co-expression models.[7](https://www.nature.com/articles/s41586-026-10789-w)\n\n## Limitations and alternatives\n\nEach method trades selectivity against practicality. Stochastic NHS and maleimide conjugation is simple and validated in ten-plus approved ADCs but yields heterogeneous, exchange-prone products: DARs range 0–9, an IgG carrying six payloads is a mixture of approximately 120 million regioisomers, and random modification near the complementarity-determining region can reduce binding affinity.[8](https://academic.oup.com/abt/article/8/2/157/8115463?searchresult=1) • [5](https://link.springer.com/article/10.1007/s11095-014-1596-8) • [3](https://royalsocietypublishing.org/rsos/article-pdf/doi/10.1098/rsos.211563/994493/rsos.211563.pdf) • [23](https://pubmed.ncbi.nlm.nih.gov/33644685/) [Maleimide](https://www.edgepedia.org/maleimide) thiol exchange is the best-documented instability: the thiosuccinimide adduct undergoes retro-Michael deconjugation, and a Pfizer study found trastuzumab–mc-vc-PABC-drug lost almost 100% of its DAR after 144 h in human plasma; self-hydrolyzing maleimides, introduced by Lyon, Setter, and colleagues in 2014 in [Nature Biotechnology](https://www.edgepedia.org/nature-biotechnology), improve ADC stability.[9](https://pubs.rsc.org/en/content/articlepdf/2021/sc/d1sc02973h) • [24](https://doi.org/10.1038/nbt.2968) Site-specific routes give homogeneous product but mostly remain proof-of-concept pending clinical validation, except engineered-cysteine conjugation.[25](https://www.tandfonline.com/doi/abs/10.1080/14712598.2024.2305266) Enzymatic methods impose sequence motifs and, for sortase, C-terminal placement, and large nucleophile excesses.[5](https://link.springer.com/article/10.1007/s11095-014-1596-8) Bioorthogonal ligations are constrained to aqueous, near-neutral, sub-37 °C conditions and vary in rate over six orders of magnitude.[13](https://pmc.ncbi.nlm.nih.gov/articles/PMC10665463/)\n\n## References\n\n1. [Bioconjugation and crosslinking technical handbook (Thermo Fisher)](https://assets.thermofisher.com/TFS-Assets/BID/Handbooks/bioconjugation-technical-handbook.pdf)\n2. [Advances in Bioconjugation (Kalia & Raines, Current Organic Chemistry, 2010)](https://europepmc.org/article/pmc/2901115)\n3. [An overview of chemo- and site-selectivity aspects in the chemical conjugation of proteins (Royal Society Open Science, 2022)](https://royalsocietypublishing.org/rsos/article-pdf/doi/10.1098/rsos.211563/994493/rsos.211563.pdf)\n4. [Development and Recent Advances in Lysine and N-Terminal Bioconjugation for Peptides and Proteins (Molecules, 2023)](https://www.mdpi.com/1420-3049/28/3/1083)\n5. [Methods to Make Homogenous Antibody Drug Conjugates (Pharmaceutical Research)](https://link.springer.com/article/10.1007/s11095-014-1596-8)\n6. [Advances in Payload and Linker Designs for ADCs (AAPS PharmSciTech, 2026)](https://link.springer.com/article/10.1208/s12249-026-03445-z)\n7. [Modular in vivo antibody–ADC click to reverse drug resistance in tumours (Nature, 2026)](https://www.nature.com/articles/s41586-026-10789-w)\n8. [Review of conjugation technologies for antibody drug conjugates (Antibody Therapeutics, 2025)](https://academic.oup.com/abt/article/8/2/157/8115463?searchresult=1)\n9. [Recent developments in chemical conjugation strategies targeting native amino acids in proteins and their applications in antibody–drug conjugates (Chemical Science, 2021)](https://pubs.rsc.org/en/content/articlepdf/2021/sc/d1sc02973h)\n10. [Bioorthogonal Chemistry and Its Applications (Bioconjugate Chemistry, ACS)](https://pubs.acs.org/doi/full/10.1021/acs.bioconjchem.1c00461)\n11. [M. J. Hunter, M. L. Ludwig (1962). The Reaction of Imidoesters with Proteins and Related Small Molecules. Journal of the American Chemical Society.](https://doi.org/10.1021/ja00877a016)\n12. [Gary E. Means, Robert E. Feeney (1990). Chemical modifications of proteins: history and applications. Bioconjugate Chemistry.](https://doi.org/10.1021/bc00001a001)\n13. [Recent Advances in Bioorthogonal Ligation and Bioconjugation (PMC)](https://pmc.ncbi.nlm.nih.gov/articles/PMC10665463/)\n14. [Site-specific labelling of native peptides and proteins: chemical and enzymatic strategies (Beilstein J. Org. Chem.)](https://www.beilstein-journals.org/bjoc/articles/22/67)\n15. [Site-Specific Antibody–Drug Conjugates: The Nexus of Bioorthogonal Chemistry, Protein Engineering, and Drug Development (PMC)](https://pmc.ncbi.nlm.nih.gov/articles/PMC4335810/)\n16. [Alan Lyons and colleagues (1990). Site-specific attachment to recombinant antibodies via introduced surface cysteine residues. Protein Engineering.](https://doi.org/10.1093/protein/3.8.703)\n17. [Felix F. Schumacher and colleagues (2014). Next generation maleimides enable the controlled assembly of antibody–drug conjugates via native disulfide bond bridging. Organic & Biomolecular Chemistry.](https://doi.org/10.1039/c4ob01550a)\n18. [Site-selective modification strategies in antibody–drug conjugates (Chem. Soc. Rev., 2021)](https://pubs.rsc.org/en/content/articlehtml/2021/cs/d0cs00310g)\n19. [Xiuru Li, Tao Fang, Geert‐Jan Boons (2014). Preparation of Well‐Defined Antibody–Drug Conjugates through Glycan Remodeling and Strain‐Promoted Azide–Alkyne Cycloadditions. Angewandte Chemie International Edition.](https://doi.org/10.1002/anie.201402606)\n20. [Jun Y. Axup and colleagues (2012). Synthesis of site-specific antibody-drug conjugates using unnatural amino acids. Proceedings of the National Academy of Sciences.](https://doi.org/10.1073/pnas.1211023109)\n21. [Hongyuan Mao and colleagues (2004). Sortase-Mediated Protein Ligation: A New Method for Protein Engineering. Journal of the American Chemical Society.](https://doi.org/10.1021/ja039915e)\n22. [Simone Jeger and colleagues (2010). Site‐Specific and Stoichiometric Modification of Antibodies by Bacterial Transglutaminase. Angewandte Chemie International Edition.](https://doi.org/10.1002/anie.201004243)\n23. [Site-specific conjugation of native antibody (PubMed-indexed review abstract)](https://pubmed.ncbi.nlm.nih.gov/33644685/)\n24. [Robert P Lyon and colleagues (2014). Self-hydrolyzing maleimides improve the stability and pharmacological properties of antibody-drug conjugates. Nature Biotechnology.](https://doi.org/10.1038/nbt.2968)\n25. [An overview of site-specific methods for achieving antibody drug conjugates with homogenous drug to antibody ratio (Expert Opin. Biol. Ther., 2024)](https://www.tandfonline.com/doi/abs/10.1080/14712598.2024.2305266)\n\n---\n*Topic: Encyclopedia › Physical world and mathematics › Chemistry › Chemical principles and methods › Chemical synthesis*\n\n*Initially written Sep 29, 2026 · Edited: Oct 15, 2026*\n\n*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*\n\nLicense: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license\n", "same_as": [], "url": "https://www.edgepedia.org/bioconjugation", "markdown_url": "https://www.edgepedia.org/bioconjugation.md", "license": { "name": "Edgepedia Community License 1.0", "url": "https://www.edgepedia.org/edgepedia/license", "summary": "Free with credit, commercial use included. AI training is open to everyone. For other uses, organizations over USD 100M in revenue or 100M monthly users license separately.", "spdx": "LicenseRef-Edgepedia-Community-1.0" }, "credit": "\"Bioconjugation\", Edgepedia (EdgeChat), https://www.edgepedia.org/bioconjugation. Edgepedia Community License 1.0.", "credit_md": "\"[Bioconjugation](https://www.edgepedia.org/bioconjugation)\", Edgepedia (EdgeChat), [https://www.edgepedia.org/bioconjugation](https://www.edgepedia.org/bioconjugation). [Edgepedia Community License 1.0](https://www.edgepedia.org/edgepedia/license).", "credit_html": "\"Bioconjugation\", Edgepedia (EdgeChat), https://www.edgepedia.org/bioconjugation. Edgepedia Community License 1.0.", "speakable": "Bioconjugation is the chemical joining of molecules by a covalent bond in which at least one partner is a biomolecule, producing antibody–drug conjugates, fluorescent probes, and biotinylated proteins." }