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I have purchased your vpx recombinant protein a long time ago (CSB-EP323941SHD; Lot#: E051453) and I would like to see the COA for the batch we received. Can you please provide this COA. Also, was the protein sent to us liquid or lyophilized? Please provide the formulation of the buffer that was used as well as Endotoxin level (if tested).
We recently received your protein CSB-EP323941SHD, lot 03767, which was concerned because this lot was more concentrated than the previous lots they received. We want to verify the concentration, and were wondering if you had a recommended commercial assay that we would be able to purchase to confirm the concentration found by your team. Would you be able to advise on the Bradford kit you guys used to determine the concentration of this lot?
Lot# 03767 concentration question. Hello, My Certificate of analysis for this lot says 0.3 mg/ml. This is my third lot that I have received in the past year, and this lot seems to be more potent than the other two lots when run in the same assay. I see that you test concentration by using the Bradford Method. I have two topics that I would like to know more about: 1) Do you have more specific data for this lot--was it closer to 0.34 mg/mL--or does this assay only give results to one significant figure? 2) Do you use a commercial test kit to measure the concentration? I see that Thermal Fisher Life Technologies has several types of test kits made by Pierce available. Do you know if their cat #23236 Coomassie Plus (Bradford) Assay Kit will give similar concentration results as what you perform? Do you have a suggestion of a commercial test kit that I could use to check the protein concentration myself? Thank you for your help with this inquiry.