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Questions related from Pongpawan Sethanant
Dear all, I would like to know whether addition of IPTG before (37 degC) and after lowering induction temperature (16 degC) affect protein expression levels? *add IPTG before = add IPTG when 37...
10 October 2018 9,932 7 View
What techniques could be used to identify the number of zinc atoms present within a protein? Some techniques that I could think of are PAR-PMPS assay, crystallography, and atomic absorption. I...
08 August 2017 4,198 4 View
Dear all, I am currently purifying a small protein which contains 5 cysteines. The purification flowis: Ni-NTA -> His tag removal by TEV cleavage -> remove TEV protease by Ni-NTA column...
03 March 2017 2,000 4 View
Dear all, I am using BL21(DE3)pLysS to express my protein (as indicated by the red arrow). Both pictures showed significant protein expression pre- and post- induction. The only difference between...
10 October 2016 4,833 6 View
I would like to perform a native PAGE of my small protein ~6.5 kDa to see its physiological oligomeric state. Normally, I use tricine SDS-PAGE to separate the proteins but I am not sure whether...
09 September 2016 628 4 View
Dear all, I am expressing a virus protein about 9 kDa on a 16% tricine gel (150V constant). I induced protein expression with 0.5 mM IPTG and collected the cells pre- and post- induction. The...
05 May 2016 8,158 7 View
Dear all, I accidentally mixed Ni-NTA beads with E. coli cell lysate but has a problem with separating them. Is there any way to separate them so that I can regenerate Ni-NTA beads for...
04 April 2016 6,151 7 View
Dear all, I am using ammonium sulfate precipitation for my assay and my protein started to precipitate at 50%. Therefore, is 50% ammonium sulfate considered concentrated? Thank you very much
01 January 2016 4,585 8 View
In crystallography, including other approaches to resolve protein structures, is there any explanation why the wavelength that we use must equal to interatomic distances? Is there any way to...
11 November 2015 6,343 4 View
I'm not quite sure whether this is practical or not but I am looking for a method to separate antigen-antibody complexes without denaturing them, especially the antigen (which is a protein)....
03 March 2015 3,279 21 View
I am biotinylating my monoclonal antibodies at the moment. However, I have biotinylated two batches of them and the reactivity & background(non-specific binding) seems to be...
02 February 2015 2,953 7 View
Hi, I am biotinylating my monoclonal antibodies(mAbs) (both IgGs & IgMs) with biotin(EZ-Link® Sulfo-NHS-LC-Biotin) from Pierce Biotechnology, Inc. However, the manual I attached below...
02 February 2015 6,784 13 View
Why are enveloped viruses that are made up of lipid bilayers less tolerant than naked viruses even though those enveloped viruses also have a capsid? Are there any specific explanations for...
01 January 2015 4,519 6 View
When I'm conducting an ELISA experiment, I don't use up all of the 96-wells at once. So, I cover the other parts that I don't use with tape. However, when I wash the wells with PBS-Tween20 (with...
12 December 2014 6,810 4 View
