PEG coated Fe3O4 nanoparticles in aqueous NH3?

Hello, I synthesized PEG coated Fe3O4 nanoparticles by coprecipitation methods and I would like to ask whether they can be dispersed in aqueous NH3 since they have a PEG coating and theoretically...

06 February 2021 5,217 4 View

Is there such a function? Is it unique?

21 January 2021 8,962 13 View

What are the current developments in terms research and publications in anthropology in general and social anthropology in particular?

I am interested in examples of anthropological methods that have been applied across different disciplines, for exmple in mathematics education.

20 January 2021 3,090 3 View

How did the tests or exams get to Latin America, specifically the written tests?

I am looking for some bibliographic references that explain how tests or exams (measurement and assessment in education) came to Latin America, specifically written tests. I would like to know if...

13 January 2021 8,607 0 View

Is this true for all values c > 0?

25 December 2020 3,621 45 View

Can children from 1 year old to 15 years be given MODANA and Pfizer Anti-COVID-19 vaccine?

The clinical disease of COVID-19 has been low in children generally and vaccine has been develop.Any evidence of its safety,efficacy and risk for allergy in children? any exemption for children...

23 December 2020 7,177 12 View

Can large samples be stored at -20 degrees prior to RNA extraction?

As part of a Covid project we are sampling urban rodents and performing RNA extractions and serology work. We have too many samples to store at -80 and have opted to perform extractions the same...

15 December 2020 5,252 2 View

Substrate functionalization and antibody deposition for biosensor work?

Hello, I am a bio student working in a lab on his free time and I just started working with an engineering group on sensors. My questions are: 1)Functionalization steps and what are the best...

21 November 2020 7,996 2 View

Why am I seeing RED fluorescence in control non transgenic plants?

Hi experts, I have cloned the DsRED gene into a plant vector under 35S promoter and used it for direct seed transformation of Chenopodium quinoa. When I checked the potential transformed...

24 October 2020 4,775 3 View

Do you think there are any prospects for hydrogen as an alternative to natural gas when operating a gas turbine?

At the moment it is very expensive, the price of 1 kg of hydrogen is from $ 2-5. Are there any prospects for green hydrogen? or will we extract hydrogen from gas? what promising technologies can...

19 October 2020 1,954 7 View

During an anti-His capture ELISA has anyone had issues with histidine residues from secondary antibodies non-specifically binding?

Hi, Hope you can help. Currently been running some sandwich ELISA assays where I coat with anti-His, block and then capture His-tag protein and then sera and then anti-bovine monoclonal...

07 February 2021 7,101 1 View

Which procedure should I perform in an azo coupling reaction where histidine and tyrosine are used as the coupling agent?

I used L-Histidine and L-Tyrosine as coupling agent for azo coupling reaction and sodium hydroxide solution to adjust pH. Although color change was observed during the coupling, no precipitate...

26 May 2020 8,342 7 View

What is the reason of big variations in Biuret total protein assay?

Hello. I used from Thermo Scientific BCA kit and Sigma protein STD 2 mg/ml (0-2000 ug/ml) and prepared a lot of dilutions from my sample (up to 1-64). I had a different final concentration on my...

18 March 2020 488 3 View

Purification of histag protein using HISTRAP HP (GE). What is the best lysis buffer and which protocol may be most suitable?

Purification of histag protein using HISTRAP HP (GE). I am working with insect cells (Tn5B) and my antigens are expressed in the nucleus. I am having difficulty lysing the cells because we have no...

10 March 2020 8,609 2 View

Is neccesary to add methionine after BamH I cloning site in a pRSET A vector in orther to make the expression work?

Hello, I am trying to express a fusion protein using a pRSET A vector in C41(DE3) E. coli strains. I have tried many ways and I am trying to see if my sequence is correct. My question is if it is...

13 January 2020 7,901 2 View

HPLC method for the detection of aromatic amino acids, Histidine and benzoic acids?

Dear all, I am growing genetically modified S. typhimurium SL1344 cells in a chemically defined medium in a bioreactor. The cells have a deletion in the aroA gene, rendering them auxotrophic...

11 December 2019 1,868 3 View

HPLC method for the detection of aromatic amino acids, Histidine and benzoic acids?

Dear all, I am growing genetically modified S. typhimurium SL1344 cells in a chemically defined medium in a bioreactor. The cells have a deletion in the aroA gene, rendering them auxotrophic...

10 December 2019 2,488 3 View

Antibody for internal 10x his tag (deca histidine tag) ?

I am looking for the antibody or reagent that allows the imaging (immunostaining or western blot) of internal 10x his tag. I tested several his-tag antibodies to see them by western blot but...

07 August 2019 9,763 3 View

One of the synthesised organic compound is having a mass of 9 Da more in LCMS and also other higher order mass are found, what can be the reason?

I have synthesised a benzimidazole derivative from histidine and o phenylenediamine. product was precipitated with acetone. Theoretical mass expected is 227 Da, But I am getting the mass of 236...

18 March 2019 3,878 3 View

Can water act as proton donor during the catalytic process of epimerization?

02 March 2019 5,922 3 View