Can anyone help me to remove a hydrophobic peptide from C18 column?

I have injected a hydrophobic peptide into analytical C18 column and i have tried to cleaning the column applying a lot of protocols using acetonitrile, methanol, isopropanol, but in the blank...

05 January 2021 3,305 3 View

Could you help with a doubt regarding UDF velocity inlet profile with multiphase mixture (Ansys Fluent)?

We are two undergraduate students seeking for help!!! We are trying to simulate a laminar flux through a 3D pipe (25 cm long, 2 cm of diameter) consisting of a multiphase flux (air and water). We...

23 November 2020 3,918 3 View

What is the role of Digital Services in Crisis, Disaster, and Emergency Situations?

06 January 2020 7,241 4 View

How to dissolve Ibuprofen?

I need to obtain IBU aqueous solution. Some papers report that they dissolve it in water/methanol (90/10). But it did not work. What to use to dissolve it? Some buffer or NaOH? Or maybe some salt....

05 May 2019 6,575 1 View

How come conductivity increased at very low concentrations of CuSO4 after sorption of activated carbon?

I was investigating the sorption of activated carbon on different concentrations of copper(II)sulfate and came across rather unexpected results where the conductivity increased at 0,00001 , 0,0001...

24 November 2018 6,855 3 View

What is a good cycling method for 27F and 519R primers? Tm is 56 and 66, can they be used as a pair?

I'm trying to generate a smaller fragment of 16S from a water sample, so it can be NGS amplicon sequenced. The limit of that service is about 500bp.

14 March 2018 8,032 2 View

Can I use aneuploidy for crossing?

Dear Collegues, we are going to make segregating population of tea plant (camellia sinensis) for genetic research. we need 200 progenies. Can we use aneuploid cultivar as one of the parents to...

19 October 2017 8,451 3 View

Protocol of fungal dna extraction from plant leaf tissue?

Dear collegues, Can we use protocols of DNA extraction from plant tissues (from leaves) to extract DNA of fungal pathogen which lives inside of tissue? If yes, will the quantity of the pathogen's...

11 April 2017 8,448 31 View

If I have low bootstrap values in a ML tree, does it mean that there is no separation between different genera?

I have a maximum likelihood tree (18S and COI) for a nematode family which contains 4 different genera. The bootstrap values were very low and all the 4 genera are intermingled in both trees with...

27 June 2016 593 5 View

Why does the PCR not work occasionally?

Dear collegues! we extracted RNA from apple peel. We need clean RNA without DNA contamination, so we check our RNA samples by PCR. Samples are fresh. and reagents are the same. BUT one time PCR...

24 March 2015 4,855 12 View

What is the right way to conjugate two acids?

How to conjugate two acids with amine linker?

18 February 2021 4,083 2 View

Mixture neutralization after Boc deprotection ?

I am performing a Boc-deprotection with HCl in organic solvent (dioxane or Ethylacetate) but would like to isolate the free amine. Several problems: - Neutralizing with inorganic base as NEt3...

18 February 2021 3,366 3 View

What are the best cations for preparing competent cells, Ca2+ or Mg2+?

I have been reading various articles and most state that treatment with CaCl2 produces higher efficiency of transformation than MgCl2. Can anyone explain why Ca2+ is better than Mg2+ at...

16 February 2021 8,519 5 View

What is the role of ether solvent (such as THF) in Sonogashira coupling?

Can Amine (such as Et3N) be used as solvent as well as base for the Sonogashira Coupling? How to decide the amount of solvent to be used in any reaction? Does the amount of solvent affect the...

14 February 2021 4,018 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

Which solvent is suitable for product precipitation if reaction has been performed in toluene?

If condensation reaction happened between carboxylic acid and amine and amide is formed. The solvent for this reaction is toluene. After completion of reaction, how to collect product? It should...

03 February 2021 9,796 3 View

How to recrystallization amine compound and it is not soluble in common organic solvents ?

How to recrystallization amine compound and it is not soluble in common organic solvents ?

19 January 2021 671 3 View

What is the difference between soluble ions and exchangeable cations? And How to determine each of them?

I used percolation columns to reclamation saline-sodic clay soils . And my question is, What is the difference between soluble ions and exchangeable cations?

18 January 2021 6,868 3 View

Does increasing antibiotic concentration also increase plasmid production in DH5a E.coli?

Dear all, I am propagating some plasmids with a human gene and an ampicillin resistance gene. My logic is that if ampicillin concentration will be increased, the concentration of plasmid (pSF)...

14 January 2021 779 3 View

Which peak should I consider when calculating ZIF-8's crystalline size from XRD?

Hello, Using the Scherrer's equation, one could calculate, roughly, the crystalline size of ZIF-8. However, I am confused as to which peak in the XRD pattern should be taken for the calculation?...

10 January 2021 8,633 3 View