Benchmarking sample preparation/digestion protocols reveals tube-gel being a fast and repeatable method for...

Area of Science:

• Proteomics
• Analytical Chemistry
• Biochemistry

Background:

• Sample preparation significantly impacts quantitative proteomics accuracy and robustness.
• In-gel methods offer detergent compatibility but can be time-consuming (e.g., SDS-PAGE).
• Tube-gel (TG) preparation allows direct sample trapping in a gel matrix, avoiding electrophoresis.

Purpose of the Study:

• To conduct the first global label-free quantitative comparison of tube-gel (TG), stacking gel (SG), and liquid digestion (LD) methods.
• To evaluate protein identification, repeatability, and sensitivity across different sample preparation techniques.

Main Methods:

• Utilized UPS1 standard mixtures spiked into a complex yeast lysate background.
• Compared TG, SG, and LD approaches for sample preparation in label-free quantitative proteomics.
• Analyzed protein identification numbers, coefficient of variation (CV) for quantification, and detection sensitivity.

Main Results:

• TG preparation identified more yeast proteins (mean 1979) compared to SG (1788) and LD (1323).
• TG method demonstrated superior repeatability (mean CV 7%) compared to LD (10%), comparable to SG (9%).
• High sensitivity was achieved with TG, successfully detecting known variant UPS1 proteins in a complex background.

Conclusions:

• Tube-gel preparation is a highly effective and sensitive method for label-free quantitative proteomics.
• TG offers advantages in protein identification and experimental repeatability over SG and LD methods.
• This study provides a benchmark for TG method performance in complex proteomic samples.