Press Release: Columbia Biosciences and AlphaThera partner to develop range of Site-Specific Fluorescent Protein Labeling Reagents

The partnership will provide the life science market with an innovative conjugation chemistry for antibody labeling.

4 June 2024 — Frederick, Maryland, Columbia Biosciences, a biotechnology company based in Frederick, MD, announced a partnership agreement with conjugation specialist AlphaThera for the use of Columbia’s SureLight® R-phycoerythrin (PE) and SureLight® Allophycocyanin (APC) fluorescent proteins in the development of AlphaThera’s oYo-Link® Site Specific antibody labeling range of products.

Columbia Biosciences, founded in 2007, is a leading provider of antibody and protein labeling services as well as one of the largest global suppliers of the fluorescent proteins APC, PerCP, RPE, and BPE for flow cytometry.  Its fluorescent dyes and antibody conjugates are used in FDA-approved diagnostics, research applications, and clinical trials.

AlphaThera’s proprietary oYo-Link® technology provides researchers with a quick and easy, site-oriented approach to labeling antibodies for a variety of applications. The technology uses a unique Light-Activated Site-Specific Conjugation (LASIC) approach to antibody labeling which involves illumination of both the antibody and oYo-Link reagents with non-damaging Black-Light. This results in the formation of a highly stable covalent bond between oYo-Link and the Fc-binding site of the antibody. Any label that is attached to oYo-Link will therefore also be bound to the antibody’s heavy chain.

This unique site-specific labeling technique overcomes many of the common challenges that researchers face when using conventional antibody labeling techniques, such as heterogeneous products, reduced antibody functionality, and batch-to-batch variability.

In addition, oYo-Link affords several other time and cost-saving benefits for scientists, such as the ability to label extremely small amounts of antibody, as well as eliminating the requirement to purify the antibody prior to labeling.

The collaboration will provide AlphaThera’s customers with access to a new premium range of oYo-Link products for use in fluorescence-based applications such as flow cytometry, FACS and ELISA. Columbia Biosciences will use oYo-Link® reagents to expand their conjugation service offering.

John Morseman, CEO and co-founder of Columbia Biosciences commented “We are excited to expand our antibody and protein labeling service offering to include oYo-link technology.   It will allow our clients additional options in early-stage assay development and reagent selection.  We look forward to working with the team at AlphaThera to add new intense fluorophores in the near future.”

Dr. Andrew Tsourkas, Co-Founder of AlphaThera, commented, “We are delighted to be working with Columbia Biosciences to expand our oYo-Link range.  With the addition of APC and PE to our oYo-Link range, we are able to significantly broaden our customer base to include researchers working with popular fluorescence-based applications such as flow cytometry. We look forward to continuing this partnership and further developing the oYo-Link SureLight® product line.”

About AlphaThera (

AlphaThera is a US based biotechnology company specializing in antibody labeling reagents. They have developed a unique, site-specific bioconjugation method that enhances assay performance over competing labeling methods.

The company was founded by Dr Andrew Tsourkas and Dr James Hui at the University of Pennsylvania in 2016. They developed the technology of LASIC (Light Assisted Site-specific Conjugation), which led to the creation of the oYo-Link antibody labeling reagents.

oYo-Link reagents enable rapid, covalent, site-specific antibody labeling to a wide range of cargos (e.g. biotin, azide, oligos, and more) and are compatible with all common buffers including those containing Tris and/or albumin. The conjugation requires less than 30 seconds hands-on time and is complete in 2 hours. Meanwhile, it does not require antibody concentration or purification.

AlphaThera’s mission is to remove the complexity and inconsistency that has long been associated with antibody conjugations, making labeling simple, fast and site-specific.

About Columbia Biosciences (

Columbia Biosciences is a leading provider of antibody and protein labeling services.  It offers a wide range of services for the conjugation of fluorescent dyes, enzymes, oligonucleotides, and other labels to antibodies and proteins, thus facilitating their use in flow cytometry, immunohistochemistry, ELISA, and other analytical assays.  The company’s services are designed to enhance the functionality and detection capabilities of biomolecules from milligram to gram scale, in research as well as clinical applications. By employing a range of advanced conjugation techniques, Columbia Biosciences allows for tailored conjugation to meet each customer’s specific experimental needs, while its focus on quality ensures consistency and reproducibility.  The company offers a comprehensive range of services, spanning from individual conjugation projects to complete reagent development packages, and its rapid turnaround time, technical support, and streamlined workflow allow researchers to focus on moving their research forward.