• Lowest cost/sample for protein quantitation.
  
• More sensitive and consistent than the standard Bradford assay
  
• Faster than the Lowry Assay
  
• Reproducible results.
  
• Easy-to-use protocol
  
• No Buffer induced effect.

Protein concentration measurement is usually the first step in most protein analysis work-flow processes. Tthe Lowry protein assay method is very sensitive but is a two-step procedure that requires a minimum of up to 40 minutes incubation time.
The Bradford assay is more sensitive and can be read within 5 minutes. The ToPA kit and protocol is based on the Bradford assay, but it has been optimized to become more sensitive and tolerant to most of buffer systems.

As shown in the figures below ToPA reagent is suitable for accurate quantitation of proteins across a wide range of concentrations. Bench marking experiments demonstrate that ToPA outperforms the commercially available Bradford and Lowry based reagents in sensitivity and/or linearity making it the best reagent for non-fluorescence based protein quantitation in the market. For example, as little as 50 ng/mL of protein can be accurately detected with R² values of 0.9 using ToPA. By comparison, it is known that the standard Bradford is best for concentrations of ≥ 5ug/ml and the Lowry for concentrations ≥ 10ug/ml.

Figure 1: Representative standard curves obtained with ToPA protein assay reagent using protein standards (bovine serum albumin) with the following concentration ranges; A, 0.33-3,3ug/mL; B, 25-500ug/mL and C, 250-1000ug/mL

ToPA contains all the reagents, protein standards in a ready-to-use format, cuvettes (K-0014-20 and K-0014-50) and microtiter plate (K-0014-96 & K-0014-384) for easy and accurate measurement of total protein concentration. ToPA is based on the Bradford assay and specifically developed to eliminate the common errors associated with total protein quantitation.

• Quanti-Protein Assay Reagent
  
• Ready-to-Use Standard Curve Reagents
  
• 2000 ug/ml SCR
  
• Cuvettes or microtitre plates
  
• 1.5ml Assay Tubes
  
• Validated lab procedures