Selecting particular columns from large datasets (csv) using R Studio?

So I have large number of csv files (100+) in a directory with same structure and column names. The data is in time series and there are approx 30 columns/file. However i only want to aggregate...

08 February 2021 245 5 View

How much pre-PCR dilution of mixed-template DNA extracted from pollen (honey) is appropriate for Metabarcoding?

I'm working on pollen DNA metabarcoding to identify the floral composition of honey. How much pre-PCR dilution of mixed-template DNA extracted from pollen (honey) is appropriate for the...

28 December 2020 9,132 1 View

How to add two vertical and parallel Fresnel reflection coefficients to retrieve overall reflection coefficient for a right hand circular wave?

I have a problem in which a right hand circular polarized wave (GPS wave) encounters an ideal smooth plane obliquely, and then is reflected off that. To solve this kind of problems, the wave is...

28 December 2020 2,271 3 View

Which is better to focus on teaching or research for a good academic life and Why?

Which is better to focus on teaching or research for For a good academic life and Why?

26 December 2020 5,737 9 View

Is ag paste suitable for back contact on silicon wafer? or i should deposit al on the back surface using pvd or plasma sputtering?

Fabricating silicon solar cell

22 December 2020 4,906 7 View

Can only the spike protein of the virus provide immunity?

Virology, microbiology, immunology, vaccine

21 December 2020 424 16 View

Which renewable source is the best ?

wind hydro solar etc.

21 December 2020 6,360 16 View

Why is light pure energy?

light is pure because the light is the simplest electromagnetic construct but the energy of any object is also of the same kind.

20 December 2020 207 4 View

How to handle Missing Values for Skipped Questions (Systematic Missing) in R ?

10 December 2020 435 4 View

What is the best industrial emulsifier to make silicon oil in water emulsion?

I need to make long-lasting stable emulsions of 6 wt. % percent silicon oil in DI water. The previousely made emulsions using Tween and Span Emulsifiers did not remain stable after a week.

31 October 2020 3,568 3 View

What HPLC Marker(s) should be used to detect anthocyanins in a sample?

What HPLC Marker(s) or standard is used to detect and quantify anthocyanins such as Delphinidin, Cyanidin in a given sample of plant extract?

23 February 2021 1,832 4 View

Analyze anthocyanin use pH differential method?

Hello everyone. I do my anthocyanin test for biscuit incorporated with muntingia calabura fruit powder. I use ultrasonic bath for extraction biscuit powder in metanol HCl 0,1 N (1:10, w/v),...

10 February 2021 2,970 13 View

Equation to calculate Chlorophylls and carotenoids concentrations from a MeOH:HCl 1% (v/v) plant extract solution?

Hello everybody! I have performed an acidic MeOH:HCl 1% (v/v) plant extraction from Arabidopsis leaves to calculate Anthocyanins concentrations based on: Rabino, I., and Mancinelli, A. L. 1986....

25 January 2021 3,686 2 View

Does anyone know the pH-differential method?

I use the water method to extract the anthocyanidin from Peristrophe bivalvis (L.) Merr leave, then dilute 20 times with 0.025M potassium chloride, pH1.0 and 0.4M sodium acetate buffer, pH4.5...

20 January 2021 8,305 4 View

How to use plant root tissue for experimental analysis?

Hello everyone, I am working basically on plants (hydroponic culture). I want to estimate biochemicals and gene expression pattern of root tissues. My question is that how to harvest the tissues...

20 January 2021 4,443 3 View

Can anyone walk me through IHC/IF Staining of Cryosectioned Brain Tissues?

I'm looking to do some IHC/IF staining of X. laevis brains that have been frozen in OCT media for cryosectioning. I understand how to do the cryosectioning, but I am hoping for help/protocols that...

14 January 2021 9,752 2 View

Can PFA fixed rodent brain regions be used for TEM?

I am performing histology studies on rat brain, for that tissues are stored in PFA at 4oC. Is it possible that tissues stored by similar procedure can also be used for TEM studies or do we need...

20 December 2020 1,678 1 View

What Lysis for frozen tissus for nuclic acid extraction (Maxwell plus RSC FFPE kit) ?

Hello, I have a technical question for you. For RNA and DNA extraction, we use Quiagen kit with Trizol/thiocyanate de guanidine lysis. However, it's a bit long and we wanted to improve our...

14 December 2020 7,596 1 View

Can we solate viable cells from frozen xenograft tissues?

I am planning to isolate cells from frozen xenograft tissues (stored in liquid nitrogen). The tissues are stored in 10% DMSO, 30%FBS and 60% RPMI with Penn/Strep. These tissues were frozen with a...

14 December 2020 3,910 1 View

Which measurement should i use for the test of light stability? Color Value or Absorbance ?

I would like to know more about the light stability test for anthocyanin using UV light and agar solution. If we use agar solution, how can we read absorbance value? Or else can we show the light...

06 December 2020 3,538 1 View