2013 Young Investigator Award Finalist: Long Yuan

Nominee:

Nominated By:

Supporting Comments:

What made you choose a career in bioanalysis?

I was trained as a medicinal chemist in my undergraduate studies. My goal was to become an excellent pharmaceutical scientist who can design and invent new drugs to help patients, and with this goal I continued my graduate studies in medicinal chemistry. It was during my graduate studies that I learned to use LC–MS/MS and became aware of its power for detecting and measuring different molecules in biological matrices. I realized that bioanalysis can also make a significant contribution to drug discovery and development and enjoyed working on this field. Therefore, I chose and started my professional career in bioanalysis.

Describe the main highlights of your bioanalytical research, and its importance to the bioanalytical community both now and in the future.

For LC–MS/MS-based bioanalysis of proteins, achieving an efficient and reproducible digestion to generate the surrogate peptide(s) is critical. I investigated the application of pellet digestion methodology for the bioanalysis of hard-to-digest proteins (e.g., a large protein with multiple disulfide bonds). Pellet digestion was found to provide similar or better digestion efficiency for the test protein comparing with traditional digestion methods. Pellet digestion eliminates the time-consuming pretreatment steps (e.g., denaturation, reduction and alkylation) and offers a much simpler and faster digestion process. We found it to be a very useful technique for the LC–MS/MS analysis of large proteins. I also evaluated and successfully applied the use of a robotic liquid handler to automatically prepare standard and QC samples in blood and to spot the blood samples onto dried blood spot (DBS) cards. This automated sample preparation process can significantly improve the efficiency, robustness, and safety of DBS bioanalysis, and is easy to be applied by other labs. In another work, I systematically evaluated the root cause of non-linearity in LC–MS/MS bioanalytical assays and developed a strategy to predict and extend the linear standard curve range. These research projects originated from identifying potential bottle-necks or issues in my daily bioanalytical work, and they will greatly benefit my future work. I really enjoy this kind of research since it has a direct and practical impact on my daily work, and that of the broader bioanalytical community.

Describe the most difficult challenge you have encountered in the laboratory and how you overcame it?

The most difficult challenge for me has been the quantitative analysis of a monoclonal antibody using LC–MS/MS that I started working on early last year. The project is very challenging; especially since I had no experience in protein analysis, which is quite different from the analysis of small molecules. It is also very interesting and exciting. I dived into the literature, consulted with and learned from experienced colleagues, and more importantly, spent a lot of time doing experiments to gain firsthand experience. I identified some areas that I could work on to improve the efficiency and applicability of LC–MS/MS bioanalysis of proteins. As previously mentioned, I evaluated pellet digestion methodology and successfully applied this simple and fast method in the quantitative analysis of a monoclonal antibody in monkey serum. Another key challenge for LC–MS/MS-based assays is sensitivity. The highly abundant endogenous proteins in serum are digested together with the target protein and large amounts of background peptides with similar chemical properties to the surrogate peptides are generated. These background peptides can cause severe ion suppression, high background, and potential interference with the LC–MS/MS detection, and therefore decrease the sensitivity. Sample clean-up is critical for achieving a highly sensitive assay. I am currently evaluating SPE sample clean-up and the preliminary results demonstrated that SPE can remove most background peptides and improve assay sensitivity.

Where do you see your career in bioanalysis taking you?

Working in a leading biopharmaceutical company provides me opportunities to work on cutting-edge bioanalytical projects; the great atmosphere and talented colleagues motivate me to conduct my research in addition to more routine bioanalytical projects. I like this kind of research and aspire to continue my research in this field. There are many issues that remain to be investigated and solved, especially in regulated bioanalysis. Currently, the LC–MS/MS assays for DBS and protein bioanalysis still require some time-consuming and labor-intensive steps. Automation will help to make the DBS and/or protein assays as convenient and rugged as the conventional small-molecule assay in plasma, and, therefore, greatly facilitate their application. I am interested in applying automation in bioanalysis to improve the efficiency, quality, as well as the safety of the assay. For the quantitative bioanalysis of proteins using LC–MS/MS, I will continue to investigate various sample clean-up techniques (SPE, immunocapture, and other methods) to achieve better sensitivity and specificity. I hope my work can make a difference to the bioanalytical community and to the development of new medicines for patients.

How do you envisage the field of bioanalysis evolving in the future?

Driven by the innovative thinking of scientists and the development of new technologies, bioanalysis is continuously evolving through the adoption of new technologies and the exploration of new scientific fields. For bioanalysis, achieving high-quality data with improved efficiency is always the goal for us analysts. I believe automation is the key to achieve this goal, especially in the new frontiers of bioanalysis. The implementation of automation will greatly facilitate the development and application of the new technologies in bioanalysis, whereas the lack of automation may actually hinder the progress. LC–MS/MS is being investigated as an alternative technology for the analysis of protein therapeutics. LC–MS/MS-based assays allow faster method development compared to the ligand binding assay. In addition, with its high specificity, LC-MS/MS can provide unique information that a ligand binding assay cannot provide. For example, the measurements of multiple surrogate peptides from different regions of the protein can provide information on the integrity of the protein. As a complementary tool to ligand binding assays, I envisage that LC–MS/MS-based assays will be widely used for the bioanalysis of proteins in the future, especially to answer some molecular structure specific questions. Another new development in bioanalysis is DBS technology. DBS offers unique advantages with much smaller required blood volumes and much simpler storage and transportation. It will become a valuable alternative sample collection procedure.

Please list 5 of your recent publications, and select one that best highlights your career to date in the field of bioanalysis.

Yuan L, Arnold M, Aubry A, Ji Q. Simple and efficient digestion of a monoclonal antibody in serum using pellet digestion: comparison with traditional digestion methods in LC–MS/MS bioanalysis. Bioanalysis 4(24), 2887–2896 (2012).

Yuan L, Zhang D, Jemal M, Aubry A. Systematic evaluation of the root cause of non-linearity in liquid chromatography/tandem mass spectrometry bioanalytical assays and strategy to predict and extend the linear standard curve range. Rapid Commun. Mass Spectrom. 26, 1465–1474 (2012).

Yuan L, Zhang D, Aubry A, Arnold M. Automated dried blood spots standard and quality control sample preparation using a robotic liquid handler. Bioanalysis 4 (23), 2795
2804 (2012).

Yuan L, Ji Q. Automation in new frontiers of bioanalysis: a key for quality and efficiency. Bioanalysis 4(23), 2759–2762 (2012).

Yuan L, Jiang H, Ouyang Z et al. A rugged and accurate liquid chromatography-tandem mass spectrometry method for the determination of asunaprevir, an NS3 protease inhibitor, in plasma. J. Chromatogr. B. 2013, 921-922:81-86.

First choice: Yuan L, Ji Q. Automation in new frontiers of bioanalysis: a key for quality and efficiency. Bioanalysis  4(23), 2759–2762 (2012).

Reasoning: Improving efficiency, throughput, and quality of an assay is critical for bioanalysis. My research to date, as represented by the other four recent publications, focused on how to achieve an accurate and robust LC–MS/MS bioanalytical assay and how to improve the efficiency and quality of the assay. This publication summarizes my research and view on these aspects, especially the importance of automation in regulated bioanalysis.