How to use iZON qNano for zeta analyser?

More Hellen Franciane Gonçalves Barbosa's questions See All

Any suggestion of free of charge questionnaires that measure mood states?

I need a free of charge and short questionnaire that measures mood states. The questionnaire will be used as in a neuropsychological evaluation study. It is well known that mood states can...

16 January 2021 8,284 4 View

Can I ask for your suggestions in freeze-drying PCR/LAMP mixes?

We have a project on development of a dry loop mediated isothermal amplification (LAMP)-based kit for detection of plant viruses on field site. One of the challenges in this project is the...

06 September 2020 8,531 4 View

Why we use HPLC-RP to determine the purity of new chemical entities?

I don't understand why we use HPLC as method to determine the purity of NCE/drugs in medicinal chemistry if the HPLC won't show everything that could be a impurity (only compounds with UV absortion).

02 February 2020 3,135 3 View

What Statistical test do you suggest for hydrologic data series?

Hi everyone I want to apply different probability distributions to series of maximum 24 hour precipitation data, maximun and low flows, , for 100 un-gauge stations in Colombia. After I want to...

09 April 2019 8,386 5 View

Why does TFA turn light brownish a few days after opening? Is it still okay to use it ofr synthesis?

Someone help, please!!! I purchased a bottle of TFA last week and opened it to secure it with a rubber cap. I did this in a nitrogen atmosphere and also it was stored in a brownish glass bottle....

29 August 2018 9,337 3 View

Do you know of any solution adopted by island countries to avoid their disappearance caused by climate change?

As we know, some island countries like Tuvalu, Kiribati and the Maldives risk disappearing because of the climatic changes. Do you know of any solution adopted by island countries to avoid their...

27 February 2018 8,943 8 View

Are there any institutions offering doctoral or postdoctoral scholarships for foreigners in 2018?

Dear, I am looking for an institution that is offering a doctoral or postdoctoral scholarship for foreigners in the second half of 2018. I am finishing my PhD in Agronomy (Soil Science) in one of...

28 November 2017 382 3 View

Does anyone know/recommend a repeatable reference electrode for non-aqueous media other than the system Ag/AgCl in EtOH/LiCl 1 mol/L?

Solvents under test are MeOH, EtOH and acetonitrile, and support electrolytes are NH3/NH4Cl and LiClO4. It would be nice if one also indicates a good protocol for potential repeatibility check...

13 September 2017 5,016 2 View

How do I generate GOF statistics using the R-package fitdistrplus?

How do I generate GOF statistics using the R-package fitdistrplus? Here's my data and distributions to compare: Weibull distributions Dist1 - shape: 1.7914 ----- scala: 48236 Dist2 - shape: 2.1406...

15 November 2016 5,867 5 View

Is it ok to perform umbrella sampling with implict solvets?

I'm about to start protein-peptide simulations to estimate binding affinity via umbrella sampling. Is it OK to perform it using implicit salvation? Could not find works with this approach using...

08 August 2016 8,947 4 View

Buffer to disrupt platelet alpha granules for PF4 quantification?

Hello! I want to quantify by ELISA the secreted (from platelets poor plasma) and the non-secreted (from platelet lysate) PF4 before and after TRAP stimulation. I will use the ELISA from R&D...

03 March 2021 1,499 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

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

Why are my bands weird in this Agarose gel?

Can someone please give me some possible things that could go wrong? Here is my recipe: 0.5g Agarose 50 mL of TAE 1x 1 uL ethyl bromide. Gel was run at 100V for 1 hour. The buffer used is also TAE.

01 March 2021 9,952 3 View

What do I do with DLS peaks that are from the buffer?

I'm looking at the aggregation of my protein sample using DLS. Unfortunately, my buffer (20mM HEPES) also results in a set of peaks. These are at approximately 1 and 1000 d.nm. The lowest peak...

01 March 2021 9,015 2 View

What is the most suitable resuspension buffer for TCA/acetone precipitated protein?

I need to extract protein from fermented carbon sources for Bradford assay. Most researchers experiencing insolubility of pellet in resuspension buffer. Please assist me to select most suitable...

26 February 2021 7,129 3 View

What urea buffer can i use for biotagged protein extraction from streptavidin beads?

Hi all, I have been doing research on biotagged LDB1 proteins in Mel cells. I purify the proteins using M280 streptavidin beads. The yield is very low so I've been trying to optimize it by...

24 February 2021 5,749 3 View

Cloudy/high background western blot - can anyone help me?

Hi everyone! I try to detect VDR protein (~48 kDa) using Western Blot. After SDS-PAGE using 10% MP TGX Stain-Free Gel from BioRad I transferred the protein onto an metOH activated PVDF membrane...

23 February 2021 6,266 3 View

How to improve the buffer capacity of sea water?

Hello everyone I would like to improve the buffer capacity of seawater (pH ~8) in order to dissolve as much CO2 as possible without dropping the pH below 7.5 (a range between 7 - 7.5 is...

17 February 2021 2,797 2 View

Why does flow deformation occur at the test line and control line on nitrocellulose membranes (LFIA)?

I use 1% BSA in 10 mM phosphate buffer (pH 7.4) solution when striping my nitrocellulose membranes with antigens and antibodies. However, I always observe deformed flow when my sample or running...

16 February 2021 4,224 3 View