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

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

Is there a generalized method to derive current-mode model of any DC-DC converters?

Hi all, As new DC-DC converters are being proposed, associated control method should be proposed and based on the small-model signal analysis of the DC-DC converters. Using average space state...

06 January 2021 7,247 3 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

Species identification.Who can tell me the scientific names of these Gastropods?

Species identification. I've been doing research on communities of marine macrobenthos recently, but some of them can't be identified, which hinders my research. Who can help me identify these...

14 December 2020 8,357 3 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

Protein concentration decrease after dialysis?

Recently I have been involved in this problem: After expressed by adding IPTG, lysed with B-PER, and resolved with Buffer B (8M urea), incubate with Ni-NTA beads, everything looks fine. When I...

21 November 2020 7,416 3 View

How can I represent SDS-PAGE results for machine learning analysis?

I am trying to classify and analyze the results of an SDS-PAGE based array for bacterial detection using machine learning, but I have trouble finding the best way to represent the results with...

27 February 2021 9,176 3 View

Which polarizers are usually used to measure the birefringence of zebrafish muscles?

I already found several publications on that topic, however, the specifications for the used filters are often missing. Some more specific information than "fish is placed between to polarizing...

23 February 2021 1,934 1 View

How the values of errors can be calculated for thermodynamic data?

I have calculated thermodynamic parameters for surfactant solutions in aqueous and mixed alcoholic solvents. I want to calculate the value of errors in the data and represent it in the table along...

22 February 2021 239 2 View

How to calculate the Atomic Polar Tensor using DFT ?

Dear friends, I am a beginner at DFT calculation. I have done a structure optimization using DFT- B3LYP/6-31G*, Nevertheless, I don't know How to calculate the Atomic Polar Tensor (APT) in...

17 February 2021 9,082 3 View

Should I make 2 helical antennas? One for 2.4 GHz and another for 5.8 GHz?

Should I make 2 antennas, one for 2.4 GHz and one for 5.8 GHz? How should I approach the problem if I want to design the antennas which cover 400 and 900 MHz and 2.4 and 5.8 GHz? All together in...

26 January 2021 906 3 View

How to analyze non-independent epidemiological data using SPSS?

For my epidemiological data, I have used SPSS and done multiple imputation (MI) to account for the missing information. Now, I am about to analyze my data, but the issue is, that not all...

21 January 2021 3,355 7 View

SPSS - PLUM: Shall I introduce binary variables as covariates?

I am doing an analysis of interaction effects, using PLUM in SPSS. My question is if the binary variables, that i have constructed to analyze the interaction effects, should be introduced as...

17 January 2021 8,217 4 View

Guidance in choosing a column for UHPLC quantification of organic acids in cranberry and blueberry fruit?

07 January 2021 6,214 3 View

How aromatics can dissolve asphaltene ?

As we all know asphaltene is defined as " The highest molecular weight component in the crude oil that is insoluble in light n-alkanes such as n-pentane or n-heptane and soluble in aromatics such...

05 January 2021 6,822 2 View

Do you advice me how I can dissolve samples with different polarity in a culture media such as demem or emem??

We want to dissolve our research samples in cell culture media such as demem or emem. We want to conduct bio-assay guided technique to isolate bio-active compounds. But we have a difficulty to...

30 December 2020 3,590 3 View