Quality Control System

Standardized Quality Control System

The core of a membrane protein project lies not merely in achieving expression, but—more importantly—in consistently obtaining membrane protein samples of uniform quality and batch-to-batch reproducibility that meet the requirements of downstream applications. To this end, Distolife has established a quality control system covering the entire project workflow, implementing process control at critical experimental stages.

01Target Design Phase QC

Sequence & Transmembrane Region Analysis
Signal Peptide / Intra-/Extracellular Domain Analysis
Protein Construct Design
Tag & Linker Design
Mutant / Truncation Design
Expression System Selection

02Expression Phase QC

Cell Status & Culture Conditions
Transfection / Infection Conditions
Expression Time
Protein Expression Level
Membrane Fraction Enrichment
Protein Integrity

03Membrane Protein Extraction & Detergent Screening QC

Detergent Type
Detergent Concentration
Cholesterol & Lipid Composition
Salt Concentration
pH
Temperature
Auxiliary Stabilizers

Detergent Screening PriorityExtraction Efficiency→Protein Integrity→Monodispersity→Stability→Downstream Structural Compatibility

Facilities Introduction

The platform is equipped with multiple world-class instruments, covering key technological stages across the entire membrane protein CRO workflow, thereby ensuring the accuracy of experimental data and the stability and reprehensibility of production processes.

CO₂ Oscillating Incubator | Radobio All-in-One Model

AKTA Protein Purification System | GE AKTA Pure

Multi-Function Micro Plate Reader | PE High-End Detection Platform

Purification & Sample Quality Control

A multi-dimensional QC system is established during membrane protein purification, systematically evaluating samples across five key quality metrics: purity, monodispersity, protein integrity, stability, and functional status.

01Purity

Evaluating protein purity and major impurities via SDS-PAGE and other methods.

Protein PurityMajor Impurities

02Monodispersity

Evaluating protein peak shape and aggregation via SEC / SEC-HPLC.

Key FocusMain Peak PositionPeak ShapeSymmetryAggregation PeakDegradation Peak

03Protein Integrity

Evaluating whether significant degradation or abnormal cleavage occurs via electrophoresis and necessary analytical methods.

Significant DegradationAbnormal Cleavage

04Stability

Conducting stability evaluation across different conditions and batches.

Samples under Different ConditionsDifferent Batch Samples

05Functional Status

For targets with established functional assay systems, further functional validation can be performed using the following metrics.

Validation MetricsLigand BindingG Protein BindingArrestin RecruitmentIon Channel ActivityTransport FunctionLigand-dependent Stabilization

Batch-to-batch Consistency Control

Addressing clients’ key concerns about batch stability and reproducible delivery, we have moved batch QC from end-point testing upstream into the entire production workflow: every batch of membrane protein is produced under a unified SOP, with key parameters recorded and controlled.

Quality Dimension	Key Evaluation Metrics
Expression	Expression level, expression status
Extraction	Membrane protein extraction efficiency, integrity
Purification	Protein purity, recovery
SEC	Main peak ratio, peak shape, aggregation ratio
Stability	Protein status at different time points
Function	Ligand binding / activity, etc.
Sample Preparation	Concentration, homogeneity, freeze-thaw stability
Structural Samples	Particle quality, ice thickness, sample status
Batch Consistency	CV of key QC metrics and allowable deviations