Updated: Oct 3, 2025

Proteomic Profile of EPS-Urine through FASP Digestion and Data-Independent Analysis
Published on: May 8, 2021
Xiaoyue Tang1, Xiaoping Xiao2, Haidan Sun3
1Core Facility of Instrument, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, China; Medical Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
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This study introduces a new method for preparing urine samples for mass spectrometry-based proteomic analysis. The 96DRA-Urine protocol involves direct protein reduction and alkylation, followed by digestion in a 96-well format. This adaptation improves processing speed and sample throughput. The method was tested in a small-scale study for bladder cancer biomarker discovery. Results showed that urinary proteins could distinguish cancer patients from healthy individuals and differentiate cancer grades. The method shows promise for high-throughput clinical research but needs further validation.
Area of Science:
Background:
Urinary proteomics has become a valuable tool in clinical research. However, effective sample preparation remains a challenge. Traditional methods often fail to consistently yield high-quality protein and peptide samples. Prior research has shown that in-solution and ultrafilter-assisted methods have limitations in throughput and reproducibility. This gap motivated the development of new protocols. No prior work had resolved the need for a high-throughput urinary sample preparation method. Existing approaches typically require multiple steps and extended processing times. The need for a reliable and efficient method is evident in biomarker discovery studies.
Purpose Of The Study:
The aim of this study was to develop a high-throughput urinary sample preparation protocol. The researchers proposed creating a method that could streamline protein reduction, alkylation, and digestion. They focused on improving sample preparation efficiency for proteomic analysis. The motivation was to address limitations in existing methods for urinary proteomics. The study aimed to adapt a previously developed method into a 96-well format. This adaptation was intended to reduce processing time and increase throughput. The researchers also sought to evaluate the performance of the new protocol. They proposed testing the method in a small-scale biomarker discovery experiment.
The 96DRA-Urine method involves direct reduction/alkylation of urinary proteins followed by digestion on an ultrafilter unit in a 96-well format.
The 96DRA-Urine method achieved better proteomic performance than in-solution methods in qualitative and quantitative analyses.
The 96-well format was adapted to reduce buffer change time and improve sample preparation throughput.
Acetone precipitation is used to isolate urinary proteins after reduction and alkylation in the DRA-Urine protocol.
Main Methods:
The study introduced DRA-Urine, a method involving direct reduction and alkylation of urinary proteins. This was followed by acetone precipitation and digestion on an ultrafilter unit. The researchers compared DRA-Urine with in-solution and ultrafilter-assisted methods. They evaluated the methods based on qualitative and quantitative proteomic performance. The DRA-Urine protocol was adapted into a 96-well format called 96DRA-Urine. This adaptation aimed to reduce buffer change time and improve throughput. The 96DRA-Urine method was tested in a small pilot study for biomarker discovery. The researchers used label-free proteomic analysis to compare cancer and healthy samples.
Main Results:
The DRA-Urine method achieved better proteomic performance than in-solution and ultrafilter-assisted methods. The 96DRA-Urine adaptation maintained similar performance while increasing throughput. The 96-well format reduced buffer change time and improved sample preparation efficiency. In the pilot biomarker study, urinary proteins distinguished bladder cancer from healthy controls. The area under the curve (AUC) for bladder cancer detection was 0.972. The method also differentiated high-grade from low-grade bladder cancer with an AUC of 0.847. These results suggest the potential of 96DRA-Urine for clinical research applications. However, the method requires further validation for broader use.
Conclusions:
The 96DRA-Urine method may offer a high-throughput solution for urinary sample preparation. The authors suggest that the method could be useful in clinical proteomic studies. They propose that the method's performance is comparable to existing protocols. The researchers highlight the need for further verification in larger studies. The method's efficiency in a 96-well format supports its potential for high-throughput applications. The results suggest that urinary proteomes can be used to distinguish cancer from controls. The AUC values indicate strong potential for biomarker discovery. The authors emphasize the importance of validating the method in future research.
The method achieved AUC values of 0.972 for bladder cancer detection and 0.847 for high-grade cancer differentiation.
The authors suggest the method may be useful in clinical research but require further verification for broader application.