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An Improved Sample Preparation Method for Protein and Peptide Identification from Human Hair



Zheng Zhang, William E. Wallace, Guanghui Wang, Meghan Burke Harris, Yi Liu, Sergey Sheetlin, Stephen E. Stein


A fast and sensitive Direct Extraction (DE) method developed in our group can efficiently extract proteins in 30 min from a 5 cm-long hair strand. Previously we coupled DE to downstream analysis using gel electrophoresis followed by in-gel digestion, which can be time-consuming. In searching for a better alternative, we found that a combination of DE with a bead-based method (SP3) can lead to significant improvements in protein discovery from the human hair. Since SP3 is designed for general applications, we optimized it to process hair proteins following DE and compared it to several other in-solution-digestion methods. Of particular concern are genetically variant peptides (GVPs), which can be used for human identification in forensic analysis. Here we demonstrated improved GVP discovery with the DE and SP3 workflow which was three times faster than the previous in-gel digestion method and required significantly less instrument time depending on the number of gel slices processed. Additionally, it led to increased numbers of identified proteins and GVPs. Among the tested in-solution digestion methods, DE combined with SP3 showed the highest sequence coverage with higher abundances of the identified peptides. This provides a significantly enhanced means for identifying proteins and GVPs in human hair.
ACS Journal of Proteome Research


SP3 method, variant peptide discovery, protein spectrum, reproducibility, trace detection


Zhang, Z. , Wallace, W. , Wang, G. , Burke Harris, M. , Liu, Y. , Sheetlin, S. and Stein, S. (2023), An Improved Sample Preparation Method for Protein and Peptide Identification from Human Hair, ACS Journal of Proteome Research, [online],, (Accessed June 17, 2024)


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Created November 27, 2023, Updated January 5, 2024