Which Thermo Scientific protein assay is the best or the most reliable?
The choice of protein assay is dependent on preferences related to assay speed, accuracy and sensitivity, as well as interfering substances in the sample to be assayed. BCA has less protein-to-protein variation, is compatible with most detergents, and has larger working range. Pierce Bradford Plus Protein Assay Kit (Cat. Nos. 23236, A55866) is compatible with reducing sugars, is more sensitive and is faster and easier to use. For a comparison of different protein assays and compatible reagents, see our Tech Tip: Protein Quantitation Assay Compatibility Table (https://assets.thermofisher.com/TFS-Assets/LSG/Application-Notes/TR0068-Protein-assay-compatibility.pdf).
Find additional tips, troubleshooting help, and resources within our Protein Assays and Quantitation Support Center.
What is the sample to working reagent ratio when using the BCA Protein Assay Kit?
For the Microplate Protocol the sample to working reagent (WR) ratio is 1:8 (25 µl sample plus 200 µl WR). If the sample amount is limited, a 1:20 ratio may be used (10 µl sample); in this case, however, the detection range of the assay will be limited to 125-2,000 µg/ml. For the Test Tube Procedure (Standard or Enhanced Protocols) the ratio is 1:20 (0.1 ml sample plus 2.0 ml WR). In the Micro BCA Assay Kit (for both Microplate and Test Tube Procedures), the ratio is 1:1 (1 part sample plus 1 part WR).
Find additional tips, troubleshooting help, and resources within our Protein Assays and Quantitation Support Center.
I ordered the Micro BCA Protein Assay Kit (Cat. No. 23235). However, I have limited sample volumes. Can I use the Nanodrop to measure my samples using this kit?
For performing the Micro BCA Protein Assay Kit (Cat. No. 23235) in tubes and plates, the recommended sample volumes are 1 mL and 150 µL, respectively. If you have a limited amount of sample volume, you can perform the assay using a NanoDrop, which only requires 10 µL of sample and 10 µL of the Micro BCA Working Reagent (WR). Please refer to the Protocol for BCA Protein Assay Using a NanoDrop 2000/2000c Spectrophotometer.
Find additional tips, troubleshooting help, and resources within our Protein Assays and Quantitation Support Center.
What BCA protein assay kits do you recommend for NanoDrop 2000/2000c Spectrophotometers (Cat. Nos. ND-2000, ND-2000C)?
NanoDrop 2000/2000c Spectrophotometers (Cat. Nos. ND-2000, ND-2000C) are compatible with most commercial BCA protein assay kits. We offer a number of BCA protein assay kits, including, but not limited to, the BCA Protein Assay Kit (Cat. No. J63283.QA), Micro BCA Protein Assay Kit (Cat. No. 23235, and Pierce BCA Protein Assay Kit (Cat. No 23225, 23227).
To identify, compare, and choose the best protein assay for your sample type and application, you can use our interactive Protein Assay Selection Guide.
Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.
Can you provide the shelf-life for the Pierce Micro BCA Protein Assay Kit?
The Pierce Micro BCA Protein Assay Kit is covered under our general 1-year warranty and is guaranteed to be fully functional for 12 months from the date of shipment, if stored as recommended. Please see section 8.1 of our Terms & Conditions of Sale (https://www.thermofisher.com/content/dam/LifeTech/Documents/PDFs/Terms-and-Conditions-of-Sale.pdf) for more details.
Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.
