Enzyme activity not working?

I am trying to do an enzyme assay using Wild type enzyme the protocol involves tris buffer pH 8, MgCl2, S-adenosyl methionine, Substrate, and I inititate the reaction with my enzyme, but after...

06 July 2019 6,793 3 View

Protein size decreases after mutation?

I am trying to express mutants of my protein whose size is 30 Kda... however following purification by Ni affinity column ... the SDS PAGE shows the mutants appearnig at size 20 Kda.. is there a...

04 May 2019 4,982 15 View

BL21 pLyss transformation and chloramphenicol?

Do I need to add chloramphenicol to LB agar media when trying to transform my plasmid into BL21 pLyss or I can add only the antibiotic of my plasmid?

04 May 2019 9,156 5 View

Why protien not eluted after changing buffer ?

II am currently working on a protien to be crystallized. The protien is bound to FAD, that's why when I purify the protein with Ni affinity column its colour was yellow . but surprisingly, after...

07 August 2018 4,263 4 View

How to make protien soluble during expression ?

I am trying to express and purify a protein after doing all the steps and purify using Ni affinity column but after doing the SDS PAGE I found that the amount of protein in the elute is very...

05 June 2018 8,503 6 View

Use of precukture ?

I want to ask why we always do a starter preculture step during protein expression ? Why don't we just start the main culture directly ?

04 May 2018 4,468 2 View

Protien not purified using ion exhange?

I am trying to purify a protein..First I run Ni affinity column and the protein was eluted with KPB pH7.9, imidazole 500mM and glycerol ..then I diluted with No Salt buffer containg 50mM TrisHCL...

04 May 2018 5,921 8 View

Chemical shift of acetyl gp?

what is the carbon nmr chemical shift of methyl gp in acetyl gp

11 December 2017 9,435 3 View

Methoxy gp on aromatic ring ?

If i have an aromatic ring with methoxy gp on it and 3 aromatic protons in ortho, meta and para position ..Is there an explanation for why the ortho proton appears at lower chemical shift than...

09 October 2017 8,721 3 View

Isolation of soil microbes?

I have cultured soil on 2 medium .. humic acid medium and chitin agar medium for culture of fungi and actinomycetes.. the question is .. how can i know the colon grown is fungi or bacteria .....

08 September 2017 4,071 6 View

Dear all, I was wondering if anyone knows whether MGLtools and Autodock can run on Mac OS?

I have tried to download the 64-bit version of MGLtools however, as many times as I have downloaded and uninstall the programs, an error arises that the app needs to be updated. Thank you.

03 March 2021 5,997 2 View

Buffer Exchange using column packed with sephadex G-25 effect on protein concentration?

Hello, If i am doing a buffer exchange for an antibody of 1mg/mL, does the elution lose protein in the process of buffer exchange? For example, if i flow through 500 uL of 1mg/mL sample, and...

03 March 2021 6,299 3 View

I got 02 moderator values defining Johnson-Neyman significance regions. Is it an error?

Hi everyone, I am conducting research for my Master's thesis. I am using PROCESS by Johnson-Neyman to analyze my Moderator model. I test the relationship between Public Service Motivation and...

03 March 2021 2,350 2 View

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03 March 2021 5,360 2 View

Do I need to do linear regression before running mediation analysis using PROCESS MACRO by Hayes ?

I just wanted to check if I need to run a linear regression separately if I am using PROCESS MACRO to run mediation analysis. Thank you.

02 March 2021 4,359 3 View

Waters 2707 HPLC autosampler problem?

I am using a 2707 waters HPLC device. When I try to inject a sample, it says missing plate or rack. I changed the needle and calibrated its position but I still get the same problem. I even get...

02 March 2021 1,408 1 View

Do I need to strip the PVDF membrane before staining it with colloidal gold?

Dear Colleagues, After running Western blot on PVDF membrane and detection using ECL, I would like to stain my PVDF with colloidal gold to be able to allign the ECL image with total proteins on...

02 March 2021 7,829 3 View

PACYC PCR not working after several attempts. Would anyone have any suggestions?

So, I have been trying to run a pACYC PCR which will be used later on for a Gibson Assembly. However the PCR is not working. I have already tried gradient PCR and changing extension time; however...

02 March 2021 1,146 2 View

How optimize the Size Exclusion Chromatography?

Hello! I'll do a size exclusion chromatography, but I only have an open column, and I'll perform the peptide extraction from yeast, using buffer lysis (sodium phosphate 50 mM/NaCl 30 mM/DNAse and...

01 March 2021 2,215 2 View

What SPSS analysis should I run with one IV (with two levels) and two DVs?

Hi, I am trying to figure out which test would be most appropriate to run for the following question: Is there a difference in task blood pressure between smokers and non-smokers? There are two...

01 March 2021 8,235 2 View