HeLa Protein Digest Standard

In modern proteomics research, liquid chromatography-mass spectrometry (LC-MS) has become a core tool for high-throughput and high-sensitivity analysis of complex samples. However, ensuring instrument stability and data reproducibility remains a major challenge for researchers. Standardized quality control samples play a crucial role throughout the experimental workflow, particularly in method development, platform comparison, and data calibration.

 

HeLa cells (a human cervical cancer cell line) are among the most commonly used models in life science research, featuring a broad expression profile and a stable genomic background. They are widely applied in basic biology, drug development, and proteomics studies. Protein digests derived from HeLa cells have become important reference materials for performance monitoring and method optimization in mass spectrometry platforms, due to their complex protein composition, rich post-translational modifications, and high batch-to-batch consistency.

 

MtoZ Biolabs, specializing in proteomics sample preparation and standard material development, offers HeLa protein digest standard specifically designed for mass spectrometry applications. These standards are ideal for system evaluation, method development, and data comparison, providing high-quality and stable reference baselines for experimental workflows.

 

Product Overview

The HeLa protein digest standard from MtoZ Biolabs is derived from the cultured and lysed HeLa S3 cell line. The entire process follows a standardized protocol, including protein extraction, quantification, dual enzymatic digestion (Lys-C and trypsin), and post-treatment steps. The final product is a lyophilized peptide mixture, optimized for convenient storage and transportation.

 

The HeLa protein digest standard undergoes rigorous quality control to ensure a broad peptide composition, high digestion efficiency, minimal batch-to-batch variation, and the absence of salts and detergents that could interfere with mass spectrometry analysis. It is ready-to-use for LC-MS applications and serves as an ideal positive control, quality control sample, or method development material for proteomics laboratories.

 

Protocol

The HeLa protein digest standard provided by MtoZ Biolabs is supplied in a lyophilized powder form. It is easy to use and suitable for routine LC-MS/MS workflows. The recommended usage steps are as follows:

 

1. Sample Reconstitution

It is recommended to reconstitute the lyophilized powder using 0.1% formic acid (v/v) or 0.1% trifluoroacetic acid (TFA) aqueous solution. Add 20-100 µL of solvent per vial to achieve a peptide concentration of 0.1-1 µg/µL. The final volume can be adjusted flexibly based on experimental needs.

 

2. Injection Preparation

For conventional LC-MS analysis, an injection amount of 0.5-2 µg of peptides per run is recommended.

 

3. Instrument Analysis

Use a standard nano-liquid chromatography (nanoLC) system coupled with a high-resolution mass spectrometer (e.g., Orbitrap, Q Exactive, or TripleTOF) for analysis. A reversed-phase gradient of 15-60 minutes is recommended, with the specific elution profile adjusted according to column length and system performance.

 

4. Data Analysis and Quality Control

It is recommended to search against a standard protein database (e.g., Swiss-Prot Human) for database identification. Key QC metrics such as peptide coverage, retention time shift, MS intensity distribution, and digestion efficiency can be monitored accordingly.

 

Features and Benefits

The HeLa protein digest standard launched by MtoZ Biolabs offers multiple advantages in quality control and experimental compatibility:

 

1. Consistent Source and Clear Background

Utilizes stably passaged HeLa cells as the protein source, with traceable cell origin to ensure batch-to-batch consistency.

 

2. Standardized Digestion Workflow

Employs optimized trypsin digestion conditions to ensure broad peptide distribution and good integrity, suitable for various protein quantification and quality control applications.

 

3. High Experimental Compatibility

Can be used as a reference sample for MS identification/quantification with excellent compatibility across experimental workflows.

 

4. Easy to Operate and Ready-to-Use Design

Available in ready-to-use liquid or lyophilized powder form for ease of use and seamless integration into existing workflows.

 

5. Stringent Quality Control for Consistency Assurance

Each batch is validated by SDS-PAGE, BCA protein quantification, and LC-MS analysis to ensure consistent, reliable product quality.

 

Applications

This standard demonstrates broad applicability in the following areas:

 

1. Peptide Quantification Standard

Serves as a reference for calibration curve construction, improving the accuracy and reproducibility of peptide quantification results.

 

2. Mass Spectrometry Quantitative Method Development

Used for method validation, platform performance evaluation, and peptide selection; especially suitable for quantitative strategies such as DIA, PRM, and MRM.

 

3. Antibody Screening and Validation

Provides a consistent peptide background for antibody development or validation assays, facilitating the assessment of antibody binding specificity.