The Thermo Scientific Pierce HeLa Digest/PRTC Standard is a validated complex mammalian protein digest containing additional PRTC heavy isotope-labeled peptides designed for LC/MS performance testing.

Features of HeLa Digest/PRTC Standard include:

• Convenient—pre-mixed formulation of HeLa digest and PRTC standard in a ready-to-use format
• Informative—enables robust performance assessment of LC/MS instruments
• Verified—high-quality, consistent mixture documented via lot-specific certificates of analysis
• Stable—provided in a lyophilized format

The Pierce HeLa Digest/PRTC Standard is a lyophilized mixture of 10 μg of HeLa protein digest with 5 pmol PRTC peptides to assess chromatography MS instrument performance. The protein digest is derived from a well-established adenocarcinoma reference HeLa S3 cell line that expresses over 15,000 proteins with relevant post-translational modifications. This complex digest is an ideal standard for complex proteome mass spectrometry applications.

The included Pierce Peptide Retention Time Calibration Mixture contains 15 synthetic heavy isotope-labeled peptides mixed at an equimolar ratio that elute across the chromatographic gradient. The observed retention times and hydrophobicity factors (HFs) for these calibrant peptides are fit to a linear equation to determine the slope of the retention time/HF relationship. This equation and the HF of an uncharacterized peptide are then used to predict retention time. In combination, the mixture is a powerful tool to optimize and assess LC parameters, identify the total peptide elution window, and optimize and monitor MS instrumentation.

This standard is specifically formulated for LC/MS experiments and does not contain salts or detergents. Using the standard routinely before analysis of complex samples makes it possible to monitor and normalize LC/MS performance between samples and over time.

Applications:

• Qualitative LC assessment
• QC assay tool for assessment of LC/MS system performance
• LC/MS standardization
• LC/MS method development and optimization
• Normalize results for variation in retention times and peak intensities between runs