A forum to address questions regarding methods of protein purification. | Contact experts in Protein Purification to get answers
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Questions related to Protein Purification
I have a protein labeled with a fluorescent dye (fluorescein) and I am hoping to get a quick measure of purity using TLC after dialysis. TLC is quick and easy so I am hoping to start there. What...
16 November 2020 7,434 3 View
I purchased this Merck millipore's DURAPORE PVDF 0.45 micron WH PL 13 mm hydrophobic filter instead of 0.45 um syringe filter. Now I am wondering if it is suitable to use it for purifying my...
10 November 2020 1,232 5 View
I am going to extract proteins, and for that, I will use a protease inhibitor cocktail and Phospho-Stop (from Sigma). For protease inhibitor stock solution (2x conc.), it is mentioned through the...
27 October 2020 4,482 3 View
Hello all, I'm currently working with undergraduate student-researchers (there are no graduate students at my university) to purify and characterize the drug targetability of glucokinase from pig...
26 October 2020 3,760 7 View
Hello, I am interested in producing purified Cas9 in my lab. But we are not dealing with proteins so we don't have proper settings for protein purification. It seems a step using chromatography is...
26 October 2020 10,055 3 View
We have always used Probond (Invitrogen) but Promega resin is cheaper. I was wondering how the Promega resin performs, to see if it is worth to change brands. Thank you!!
19 October 2020 4,528 3 View
Hello, I have a question for old school scientists. I read in an old book about protein purification about the vacuum dialysis method for volume reduction and buffer change. When a sample is...
13 October 2020 589 8 View
I'm currently doing protein purification. my protein size is around 42kDa, however, my protein is attached with fusion tag which are Trx-tag and His-tag at the N terminal. I did optimize my buffer...
13 October 2020 2,210 3 View
We are trying to save up on reagents and heat treatment is a promising protocol, but there are limitations with the thermostability of strand displacing DNA polymerases. Does anyone know of a...
07 October 2020 4,826 4 View
Hi All, Recently, I purified 8 proteins and stored at -20 with the elution buffer containing 20 mM Tris, 250 mM NaCl and 200 mM Imidazole. I autoclaved the buffer, so I do not know whether the...
26 September 2020 10,017 6 View
I asked for protein purification, identification and isolation of unknown proteins and test versus GS-9L other than that we already got in our patent WO/2014/040605 - form native sample of honey?!
24 September 2020 2,018 3 View
Hi all, I have a purified protein (57kDa) which tends to precipitate at 4 deg C after a week (conc. 9mg/ml). Can you please share the protocol to flash freeze protein in Liquid nitrogen and...
17 September 2020 1,623 5 View
Hello all, I frequently use the Akta purifier for protein purification and recently have been getting error messages in unicorn saying "error 2012 no response frac, 900". The frac 920 is designed...
03 September 2020 2,928 1 View
I need to concentrate DNA using filtration based purification methods. Between vivaspin and microsep which one is better for more DNA concentration output.
15 August 2020 8,378 1 View
Hi :D I'm doing purify a small protein from E. coli. From E. coli extract supernatant, I purified my protein using IMAC purification with LC. I got a single peak at chromatogram and got the...
24 July 2020 2,557 5 View
I'm purifying TB antibody and the columns we are using only seem to have a DBC of about 0.15 mg/ml. This seems very low to me, but I am a protein purification novice. Is this normal?
15 July 2020 1,557 4 View
I am trying to purify a plasma membrane protein from ecoli. I think the standard procedure for membrane protein extraction is like this: Lyse Low speed spin to clarify (eg, 5k xg for 20...
03 July 2020 6,111 3 View
I need to find the number of copies of a specific membrane protein per E. Coli cell . I've created different mutations of this proteins and I need to figure out how would these mutations affect...
01 July 2020 9,137 0 View
I am working with an unusual bacteria that is very hard to lyse. I want to extract protein and RNA from this bacteria. I need to determine the optimal lysis conditions for this bacteria, but I am...
28 June 2020 5,110 0 View
Unfortunately, our stock of Lipofectamine 2000 got contaminated by bacteria: how can I sterilize it without losing their DNA transfection properties? Do you have a Dos and Don't's list? Thank...
18 June 2020 4,091 13 View
Hello! I have some expired Ni-NTA resin (QIAGEN), and I need to purify my His-tagged protein. Does the expiration date affect the binding capacity of Ni-NTA? Thank you in advance
12 June 2020 5,973 5 View
I have a question about protein transfection. I used a reagent to transfect a protein. Can I use the same reagent for a different protein that I want to transfect in the same cell line?
01 June 2020 2,716 3 View
From my experiment, I determined MDA, AST, ALT, SOD, T. Cholesterol and HDL Cholesterol in various organs Plasma, Liver, Kidney, and Heart. To get their relationships in each of the organ, I drew...
23 May 2020 7,135 0 View
Hi, I purified a protein (about 28KD) via the following steps: 1- Firstly, I used buffer A native(Qiagen)-NaH2PO4,NACL,Immidazol,ph8 2-then after centrifuging and separating my pellet , I added...
14 May 2020 1,798 6 View