Which detergent interferes with enzymatic activity the least?

I am doing an assay for interaction with a substrate and I need a detergent that will interfere with the enzymatic activity as little as possible. What is the general recommendation in this case....

10 November 2019 9,907 6 View

Why are people using both EDTA and EGTA in a buffer?

05 June 2019 5,459 0 View

Is there a his-tagged protein standard for IMAC HPLC?

I am doing some his-tagged protein purification and I would like to see if the chromatography works by running a standard. Is there a cheap histidine tagged protein people tend to use? Also the...

03 April 2019 2,537 5 View

How to make filter tips from normal tips?

I need to get a filter of good porosity (flows well) at the bottom of a 200ul tip. I need to filter small volumes of solutions in 96 format. Any ideas? The filter needs to be inert (so C18 or C8...

31 December 2018 6,909 4 View

Please recommend a dye that can be quantified by absorption to inverstigate gel filtration desalting efficiency?

I would like to test the efficiency of desalting by a gel filtration column and I decided to check the desalting efficiency by monitoring removal of a dye through absorbance. Can anyone recommend...

01 February 2018 2,886 2 View

Can I treat protein sample as part of the water phase with chloroform-methanol protein precipitation?

03 April 2017 8,178 1 View

Offline fraction of peptides by HILIC using disposable columns?

I need to perform offline fractionation by HILIC. I have done offline fractionation using disposable RP columns (I have used home made columns with oligo R3 material, but Thermo sells disposable...

10 November 2016 4,175 1 View

Why does blocking with my immunogenic peptide cause nuclear fluorescence in ICC?

Hi all, I am validating a polyclonal antibody raised against human ANT4, through WB and ICC. In most of my controls, the antibody shows very little off-target binding, but when I pre-incubate the...

03 March 2021 5,999 3 View

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23 February 2021 4,014 3 View

How to reduce static electricity of powder after lyophilization?

I am working on synthesizing and then purifying peptides using the SPPS system. After purification of the peptide, the peptide powder is obtained using a freeze dryer. When measuring the powder,...

22 February 2021 10,099 5 View

Can we remove the fmoc group after peptide cleavage?

I have synthesized the peptide using Fmoc based solid phase peptide synthesis. Also I have cleaved the peptide from the resin and lyophilized it, but later realized that, I forgot to deprotect the...

21 February 2021 4,537 3 View

How T cells recognise non-peptide antigens?

This might sound very basic question, but please share with me an explanation of how the T cell is activated when the antigen is not a peptide? What happens? And what are the molecules involved in...

21 February 2021 564 3 View

Help with Amyloid beta detection protocol (western-blotting)?

Hi everyone, I am a first year PhD student working on amyloidosis. I would like some tips and tricks to crack efficiently my current nightmare, i.e. the western blotting of the Amyloid beta and...

11 February 2021 2,513 3 View

How to assing secondary structure to calculated peptide/protein having xyz file?

Hi, I have an optimized structure of some peptides and I would like to represent it as a secondary structure - cartoon. Ok, so server apps ask for pdb file (like Stride). I tried in different...

04 February 2021 517 3 View

Identical spectra for L- and D-peptides after they self-assemble?

Hi dear all, I need advice. I have two peptides with the same sequence but one consists of L-amino acids only and the other consists of D-amino acids only. when they self-assemble in aqueous...

03 February 2021 2,032 3 View

FLAG purification, elution doesn't have protein?

I am purifying a heterotetramer, with one subunit having a 1D4 tag and the other having a FLAG tag. I purified from Sf9 with HBS pH7.3 and 0.002%LMNG first with Anti-1D4 resin and got an adequate...

02 February 2021 3,860 1 View

How long can synthesized peptides using SPPS be stored? Storage Conditions?

I have been synthesizing peptides on resin beads. I am wondering what best storage method is there to store the beads after synthesis before cleaving. And how long can they be stored in that...

02 February 2021 5,636 5 View