[Effects of different cell lysis buffers on protein quantification]

Area of Science:

• Proteomics
• Biochemistry

Background:

• Accurate protein quantification is crucial for proteomics experiments.
• Cell lysis buffers can interfere with protein measurement methods.

Purpose of the Study:

• To evaluate the impact of various cell lysis buffers on protein quantification using the Bradford and bicinchoninic acid (BCA) methods.
• To assess the reliability of the Bradford method under different experimental conditions.

Main Methods:

• Protein concentrations of bovine serum albumin (BSA) and cell lysates were determined using Bradford and BCA assays.
• Tested lysis buffers included those for 2D differential in-gel electrophoresis and conventional 2D gel electrophoresis.
• Bradford method was also tested with freeze-thaw cycles, different colorimetric cylinders, and standard curves.

Main Results:

• The Bradford method showed 1.2 to 2-fold increases in protein measurements with different lysis buffers, correlating with BSA concentration (r=0.989–0.996, P<0.05).
• The BCA method yielded significantly higher readings, sometimes exceeding machine limits, when using certain lysis buffers.
• Protein measurements by Bradford assay remained stable across freeze-thaw cycles, different colorimetric cylinders, and standard curves.

Conclusions:

• The Bradford method is a viable option for protein quantification in proteomics research.
• Optimization of the Bradford method is necessary depending on the specific cell lysis buffer and experimental setup.
• The BCA method requires careful consideration of buffer compatibility due to potential overestimation of protein concentrations.