How to make ppb level concentration ?

Hi, I've N2 gas cylinder and 100 ppm NH3 gas cylinder. With these two cylinders, I'd like to make a ppb level (1- 100) concentration. Any idea how to do that?

01 February 2021 3,264 2 View

Whether L version and D version peptidesshould have identical NMR, especially in the state of self-assembly?

Whether L version and D version peptides should have identical NMR, especially in the state of self-assembly have to have identical NMR? How to use HRMS to confirm L version or D version...

01 February 2021 6,756 4 View

What will be the possible reasons to cause no bands on gel electrophoresis?

Hi, I am doing RNA extraction for my final year project. After extraction of RNA by using conventional method, I did quantification and qualification of RNA by using Nanodrop spec and gel...

11 January 2021 8,775 10 View

How to increase the attachment of the HEK293t cells to the glass coverslips or cell dishes?

Hey guys, I always have problems with the attachment of HEK293t cells to glass coverslips while doing IFA. They are so easy to detach from the coverslips while washing. The coverslips are already...

30 December 2020 8,381 3 View

Can anyone advise me on how to amplify V4 region of fecal DNA of dss-induced colitic mice for microbiota profiling?

Animals were fed DSS via drinking water and fecal samples were collected and DNA was isolated using Qiagen stool DNA isolation kit. The V4 region of extracted DNA was amplified with specific...

20 December 2020 1,739 3 View

Protocol for in vitro cytokine stimulation of immunized CD8+ T cells?

Hi, everyone: I want to determine whether IL-2 and IL-15 have different effects on immunized CD8+ T cell effector function. In this study, I immunize WT mice with peptide on day 0 and 7, and...

02 December 2020 9,413 3 View

Do I need to run a factor analysis on all the items used in the SEM to solve the multicollinearity issues?

Respected researchers, I conducted a SEM including 5 variables (two independent variables , two mediators, and a dependent variables), the correlations between these variables range vary from...

01 December 2020 1,338 5 View

Looking for a glass slide with very low Autofluorescence (GFP)?

Does anyone know any glass slides (thickness 0.1 to 1mm) that have very low autofluoresence (GFP). I am doing a very sensitive experiment that require my glass substrate to be as low fluoresence...

28 November 2020 1,917 6 View

Function of SDS in Northern Blot washing step?

In Northern blot, we normally use either 2*SSC+0.1% SDS or 0.1*SSC+0.1% SDS in washing step. Does anyone know what's the function of the SDS in the washing buffer? Thank you in advance

26 November 2020 2,432 1 View

How to calculate the analytical solution for the HYDRUS-3D model simulation of water and salt movement in soil?

Suppose an agricultural field with uniform soil texture and salinization. The groundwater depth is 20 meters, assuming that the depth of the groundwater and the concentration of salts remain...

25 November 2020 2,382 4 View

How to separate water from glycerol solvent in a solvent recovery vacuum distillation column?

I am currently doing my third year design project. I have been assigned to design a glycerol recovery column in vinyl acetate monomer production. The process unit before the recovery column is an...

01 March 2021 9,525 4 View

How the wettability of rock sample can be changed by ageing in pure hydrocarbon oils only?

I want to do wettability analysis of hydrocarbon oil (octane)/rock/surfactant solution system. but to do the analysis first I have to make rock surface oil-wet. Since hydrocarbon oil does not have...

27 February 2021 5,383 3 View

What are the patterns of human behavior that lead to COVID-19 infections?

Does data from contact tracing help in establishing patterns of behavior and social interactions that lead to infections? There are cases here in the Philippines where patients have no travel...

25 February 2021 9,002 13 View

How to measure angle between laser travel path and machine axis in Laser Measurement system?

25 February 2021 1,987 3 View

Multi effect distillation modeling in EES?

Dear colleagues If anyone has a model of multi-effect distillation in EES or MATLAB software, please send it to me.

24 February 2021 7,282 1 View

What is the best etching method for Mg-Ca alloy?

I have used Picral etchant (4.2 g Picric acid, 10 mL Acetic acid, 70 mL Ethanol, 10 mL distilled water) but it didn't work. Is there any alternative?

21 February 2021 2,558 5 View

How would I use a glycerol fixation to fix whole brain Drosophila tissue?

I need to take IF images with DAPI on a confocal but I need to use a glycerol fixation. Has anyone done this method before, if so how was it done? Thank you.

21 February 2021 3,081 3 View

How to dilute Toxin-DMSO solution?

I have a concentrated solution of a toxin(50 micromolar) in DMSO 100%. I need to dilute it inorder to dilute both the toxin and DMSO wich can be toxic to cells. Which would you guys recommend to...

19 February 2021 7,447 2 View

How to dissolve lyophilized silk fibroin?

Dear members of the community, I am trying to concentrate silk fibroin to 25 % (w/v). Nevertheless, i am struggling with the concentration step. I successfully achieve concentrations of 5-6 % of...

16 February 2021 1,808 1 View

I have some problems with the mass transfer part of the CFD simulation of membrane distillation.Can anyone help me?

I am working on modeling of Direct Contact Membrane Distillation system with COMSOL Multiphysics software. I have some problems with the mass transfer part of the simulation because I don't know...

14 February 2021 379 2 View