How to treat Time varying covariates in HLM analysis?

Hello, i'm currently running an analysis of longitudinal data. i'm using HLM analysis using the SAS software. the design is as follow: IV1 - time (3 time points: before\during\after stress) -...

28 November 2019 7,212 2 View

How to apply fuzzy K-means with spatial constraints in R?

Hello. I am looking for a solution in R to apply spatially-constrained clustering using fuzzy K-means (fuzzy c-means). I came across the spatialClust package, and was wondering whether anyone may...

30 October 2019 4,701 2 View

Methods for measuring N-mineralization in field sites/experiments?

A student is installing a field trial that we expect to largely impact soil moisture and temperature, and we simultaneously want to measure the secondary impacts on N-mineralization in the field....

26 March 2019 4,138 3 View

What can you tell me about an E.coli strain named Lemo21 from NEB?

I am currently trying to express human tyrosinase in E.coli and as you know this enzyme being a membrane protein it comes with a fair share of difficulties relating to expression in BL21(DE3)....

03 October 2018 6,996 3 View

Protein purification protocol?

Hello fellow scientists, here i have a bit of a seemingly demoralizing issue with protein purification. Could you please help? I have attached a commassie image for clarity. 10mM imidazole, 50 mM...

25 December 2017 3,853 4 View

What to do if the assumption of Homogeneity of variance has been violated - Three-way anova?

i have a 3-way mixed anova design: 2 IVs that are within-subject and 1 IV's that is a between-subject variable. the assumption of equality of variance (Leven's Test) was violated, as the test came...

18 August 2017 3,240 4 View

Could I have a 50-75bp band for primer dimers, even if my primers are around 20 bp long?

Hi I have problems with my PCR negative controls, Sometimes I see a band in the gel electrophoresis in these controls (same master mix that in samples but without DNA template). The band is...

14 June 2017 4,540 3 View

Which is the best LC method of analyzing CMC-Na in a formulation?

Formulating a drug product that has to be filtered and wanted to know if there is an easier method to assess the amt of CMC-Na chromatographically.

21 August 2016 2,347 1 View

What is a good plant analytical laboratory to farm out analyses to?

11 May 2016 7,904 5 View

How different do languages need to be before they are considered separate? What is the "taxonomy" of languages?

I have zero experience in the field of linguistics, but a paper I am writing now calls for a brief paragraph about using languages as one defining characteristic of a different cultural group....

26 April 2014 1,240 13 View

SDS page software for analysis?

I did sds page to determine the difference in protein expression between 3 types of vaccine , but i don't have scanner or densitometer available. . so i wonder if there is a software to analyze...

02 March 2021 6,270 3 View

Is There Any Feasible Method To Test Fluorescent Compounds Other Than Fluorescence Spectrometers ??

Is There Any Feasible Method To Test The Efficiency Of Fluorescent Compounds Other Than UV Spectrometers ? Suggestions Would Be Appreciated !

02 March 2021 5,785 3 View

Which transition metal salt precursor is best for doping? Why?

I would like to synthesize a transition metal doped TiO2 via solgel method. Hence, I would like to know which metal salt precursor to choose among Chloride, Nitrate, and Sulphate. A clear...

27 February 2021 4,285 3 View

Unknown debris sheets observed in cell culture flasks?

Hi, We culture neural progenitor cells in T175 culture flasks coated with PLO-Laminin. We have successfully grown these cells with our protocol for months. Recently, we observed large sheets...

25 February 2021 3,443 4 View

What is a good reagent for lentiviral plasmid transfection in HeLa cells?

I have been using Lipofectamine 2000 but was hoping there may be a better protocol or one for something like Lipofectamine PLUS reagent.

24 February 2021 1,633 4 View

Do I need to ask permission to use pictures for my questionnaire?

I would like to use some photo from a government website for my questionnaire. But, different photo is from the different owner. So, should I just get permission from that government body or still...

23 February 2021 1,631 3 View

HPLC baseline failure (ACN/Water)?

My baseline increases without any explanation, it is only fixed by changing the solution B, will it be the column? Reagents? Bomb? Detector? Solution A: H3PO4 0.01% IN WATER Solution B: H3PO4...

21 February 2021 5,656 3 View

What reaction will occur when adding hexamine into ammonium nitrate in an acidic medium?

Hello, I am investigating properties of water in oil emulsion explosives. And adding hexamine (hexamethylenetetramine) into one of the phases that are used to make the emulsion should increase the...

21 February 2021 8,680 1 View

Which transfection reagent is the best for plasmid transfection of MDA-MB-231 cell line, Lipofectamine based or other reagent suggestion?

I try to transfect MDA MB 231 cell line with a plasmid by PEI, unfortunately, the rate of transfection is low, and now I wanna find and order the best transfection reagent for this cell line and...

19 February 2021 828 6 View

No title

The regenerated cellulose film was prepared by zinc chloride/H2O system. The zinc chloride had been washed away in the regeneration process, and the wet film which was not dried had uniform...

18 February 2021 9,538 1 View