United States
ProteoStat® Superior Performance
Selected Literature
ProteoStat® Protein Aggregation Assay Flyer
100x brighter than Thioflavin T
Figure 1: Linear dynamic range of antibody aggregate detection using ProteoStat® dye, compared with Thioflavin T. Rabbit anti-goat IgG (4.26 mg/ml) was incubated in aqueous HCl solution, pH 2.7 at 80° for 90 minutes to form aggregates. The signal from the aggregate was determined after mixing aggregate with monomer at different ratios such that the total IgG concentration remained 60 µg/ml protein.
Effective over a wide pH range
Figure 2: (B) The effect of pH on the linearity of aggregation specific fluorescence.
Benchmarked with Common Excipients
Table 1: Selection of reagents and concentrations commonly used in protein formulation, tested for compatibility with the ProteoStat Protein Aggregation Assay.
* Higher concentrations of certain detergents, such as 0.2% Tween-20, may produce an increase in background signal with the monomeric protein. However, the protein aggregate signal typically remains substantially larger.
Optimal Excitation / Emission
Aggregation detection in optimal size range
Figure 4: Comparison of the optimal size range of ProteoStat® Protein Aggregation Assay relative to other commonly employed analytical methods for characterizing and quantifying protein aggregates and particles. ProteoStat® dye is ideally suited for rapid quantification of protein oligomers and subvisible particles.
Ref: J.F. Carpenter, et al.; J. Pharm. Sci. 98, 1201 (2009)
Detects Low % Aggregate in Concentrated Protein Sample
Kinetics of Aggregation Formation
Figure 5: Different stages are generally observed during the formation of protein aggregates. First, a lag time is observed during which no fibrils are formed. After a certain lag time, nucleation occurs, and fibrils start to form (growth phase). Eventually, the growth rate decreases and becomes zero, indicating either a limitation in monomer supply. The aggregation process can be accelerated by subjecting the proteins to elevated temperature.
