Questions tagged [experimental-design]

Questions on how to plan an experiment to gain the best results. Also suitable for questions on why other researchers followed a certain procedure.

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56 views

Relationship between BMI and age?

I'm trying to study how age as a confounder may affect the relationship between commute mode and BMI (and design a research proposal). To explain age as a potential confounder, I compared age to ...
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10 views

How much mice red blood cells should I dilute before counting?

I am wondering how much red blood cells I should dilute with how much PBS before counting on hemocytometer with trypan blue
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1answer
26 views

Antimicrobial susceptibility testing

To learn the Kirby-Bauer method, I've been looking at youtube videos where a bacteria's susceptibility is tested. In this video, the researcher places the discs (containing antibiotics) right after ...
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1answer
36 views

Can I imbibe seeds before sterilization?

For an experiment I want to germinate lettuce seeds. For logistical reasons it would be convenient to imbibe the seeds by placing them in the cold for 2 days, afterwards I would sterilize the seeds ...
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Most optically transparent muscle phantom?

I am trying to use Schlieren imaging techniques to visualize how a sound wave propagates through muscle tissue. In the past, when needing to experiment with muscle we would use an agar based muscle ...
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2answers
42 views

What material is permeable for plant roots, but “impermeable” for fungi & bacteria?

I'm designing an experiment where the roots of the plant will grow in a sterile environment while the shoot will grow in a non-sterile grow room. For this reason the environments of the shoot and the ...
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1answer
86 views

Question in gel chromatography experiment

Here I am trying to do gel chromatography to separate vitamin B12 and Bovine Serum Albumin (BSA) in this experiment, I am using sephacryl s-100 HR gel column my question is can I use Phosphate ...
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10 views

Explanation of why more Ca2+ ions causes longer root length in plants

This is for an experiment to test for mineral ion availabity in plants. So if there is more Calcium ions in the soil, there would be an increase in the length of the root of the plant that is being ...
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23 views

Problem with epoxy silane (Random results in glass silanization). What are crucial points to look at?

I`m trying to immobilize an antibody onto the glass surface by means of GPTOMS (glycidoxypropyl trimetoxy silane). Using the same protocol (silanization in toluene or acidified ethanol (see below)) I ...
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2answers
52 views

How would one track a mineral nutrient in a plant in order to prove that nutrient has been re mobilized?

Before abscission - senescence of a plant structural components that contain mineral nutrients (E.g. Magnesium, Potassium...) are re-mobilized from the senescent tissue and used in other plant tissue ...
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55 views

Finding total concentration of enzymes

Sorry if my question is very basic for biology majors because I am not. I am trying to build a mathematical model of a particular pathway using systems of differential equations and in order to reduce ...
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1answer
40 views

Is there anyway from which we can measure the viscosity of honey using a refractometer?

Is it possible to use a refractometer to measure the viscosity of honey because as we know, a refractometer is used to measure moisture and therefore water influences the viscosity of honey so is ...
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41 views

Monitoring fish growth

I am new to experimental design and would like to perform the following experiment but I am not sure if my setup is correct or not so far. My idea is below. Let's say you want to optimise the growth ...
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1answer
51 views

Selection marker for a cytoplasmic vector that works at low expression levels?

I need to express a selection marker on a plasmid in human cells (e.g. HEK293). However, I am using a cytoplasmic vector derived from a non-human virus with its own mechanism for transcriptional ...
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1answer
44 views

What slope do I need to prove a hypothesis? [closed]

I am conducting an experiment for school in which I am measuring people's heart rates as music plays at different tempos. My hypothesis is that as the tempo of the music increases, so will the subject'...
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35 views

Ideas for microbiology lab. Antimicrobial properties of cutting boards

I am an undergraduate student in Biology and I am trying to design a microbiology lab that will takes 3 weeks to carry out (1-2 day each week). I am going to examine the antimicrobial properties of ...
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1answer
41 views

Is there an adhesive that could used for larval fish?

I am currently working on an experimental design that requires a larval fish (~ 4mm long) to be affixed on a metal wire tip on its dorsal side. Now, I was thinking of a glue or adhesive to do the job, ...
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1answer
116 views

Will amylase inhibitors affect the colorigenic reaction between starch and iodine?

I'm doing an experiment for my IB bio EE involving colorimetry. I'm not experienced at all with colorimetry, so I'm having some trouble planning it. The experiment is on enzyme kinetics, and I'm ...
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78 views

Why didn't these scientists restore electrical activity in this pig's brain?

This experiment was published in Nature Magazine: Pig brains kept alive outside body for hours after death. The researchers used a system called BrainEx to revive certain metabolic and physiological ...
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23 views

Why don't materials and methods describe culture media in volume?

After reading several materials and methods sections of cell culture experiments, I have not seen the recipe for culture media ever described in terms of volume. Human adipose tissue was obtained ...
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1answer
27 views

Computational approaches for making hypotheses about the effects of genetic engineering? Experiment planning methods?

Let's assume that I am searching for gene editing candidates for curing human adiposis. Are there computational frameworks that can allow me to select the best candidate-genes for editing via some ...
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1answer
44 views

How can I estimate the total number of yeast cell in a medium?

So I want to run an experiment with yeast. I want to monitor the population as close as possibly in regards to its size. I am aware I could use a colorimeter or such, but I can only get a microscope. ...
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24 views

How can I approach this data that has a different total number of results between samples?

I was not sure whether I should post this in Biology Stack Exchange or Math Stack Exchange so I posted it in both. I was planning on doing a small research for my math class (a final project for the ...
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1answer
75 views

What would “N” and “V” stand for in DNA barcoding?

I'm currently looking protocol for PAT-seq, and when it talks about the barcoding that's utilized, the documentation mentions there being an "N" and "NN" in the sequence, as well as a "V". For example:...
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2k views

How can I measure the population growth of yeast?

I will soon have to carry out an experiment. I want to estimate the rate of growth of a population of yeast, although I don't know if it is possible to at least estimate the number of yeast bacteria ...
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128 views

How does the OD correlate with the number of algae cells?

My research team and I are using a spectrometer to measure the OD of an algae sample. We are trying to answer the question "Is there a correlation between OD and the number of algae cells?" What ...
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Why did scientists think humans had 100,000 genes (before the Human Genome Project)?

One of the major results of the Human Genome Project (HGP) was that humans have far fewer separate genes than previously thought. From a 2004 article about the HGP: Francis S. Collins, director of ...
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43 views

Are there situations where in vivo results work better than in vitro results would have shown?

Basically, if I have poor in vitro cell line results but decided to test them in vivo in a mouse anyway what are the possibilities of having better results in the in vivo live mouse model that I would ...
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1answer
27 views

What does $g_0$ mean for a centrifuge?

I'm about to make some Graphene Oxide and in the paper for Tour's Method it uses a centrifuge to isolate the solution. However it requires $319g_0$. What does this mean, and will a centrifuge with ...
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1answer
81 views

How can enzymes be immobilised on glass?

I’m studying a hypothetical model for urease activity, which involves fluorescence measurement, hence the need for an optical window to which the enzyme urease is immobilised. From my previous ...
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1answer
115 views

Is this experiment to check enzyme reaction rate according to substrate concentration correct?

We just had an experiment to check enzyme reaction rate according to it's substrate concentration. In the experiment, we used a varying amount of substrate and the same amount of enzyme: (1.5mm enz, ...
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1answer
544 views

How is the gradient in density gradient centrifugation made?

From the literature I read, I came to understand the following. Please correct me if wrong. In CsCl gradient centrifugation, the gradient is achieved by centrifuging the CsCl solution at high rpm, ...
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2answers
2k views

Growing bacterial culture on gelatin

I'm very new to experimental biology and don't know much about it. So, i was looking to grow some bacteria in petri dishes and looked up how to do it. Unfortunately, I'm finding it difficult to get my ...
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78 views

Electrical field stimulation of neurons: what are commonly used stimulation protocols and which are physiological?

I am doing a labproject with primary mouse nerve cultures (hippocampus and midbrain) and part of the experiments involve performing electrical field stimulation on these neurons. For now we have ...
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1answer
96 views

How does radiolabeling work?

Protein turnover can be measured by calculating the "decay" or loss of radio-labeled proteins in the blood, for example, but I am confused at how this calculation works. Wouldn't the radioactive ...
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69 views

Criticism of the significance of fMRI studies [closed]

On the german Wikipedia page on fMRI I read the following "There is some critisism of the basic assumptions and possible insights gained from fMRI studies which is based on a constructive ...
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1answer
58 views

How are fMRI responses to auditory stimuli measured?

How can fMRI experiments be conducted which measure the response to auditory stimuli (e.g. music) when the apparatus makes such loud, nasty, and distracting noises? Are there quieter MRI tomographs in ...
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1answer
60 views

Is my RNA-seq experimental design correct to use it for SNP calling?

I am a newbie here and would highly appreciate your advice about one particular experimental design. We have data from RNAseq experiment which was originally designed to assess differential ...
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2answers
1k views

Measuring the Rate of Photosynthesis

Update: I have just received a grant to pursue this research. However, I must still perform the preliminary experiment described below before dipping into my very limited funds. Thank you for any ...
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1answer
428 views

Quantifying DNA in a band on gel electrophoresis

I am a first year science undergraduate and I am just asking this as a more theoretical question rather than for carrying out a protocol, so I would appreciate if answers do not involve lots of ...
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34 views

Does vegetable oil allow methane to pass through? [closed]

I'm doing an experiment investigating how temperature affects the rate of methanogenesis. I'm using a peat sample that will be kept in a conical flask connected to a gas syringe with a layer of Janus ...
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1answer
232 views

What is sequential passaging?

I have read a journal that describes sequential passaging with the purpose of measuring resistance development in bacteria. I would like to know more about how the method works ie. what does "passage" ...
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1answer
93 views

Webtool to design guide RNA (gRNA) for use with CRISPR-AsCpf1?

My goals are to use a free webtool to: Identify guide RNAs (direct-repeat sequence followed by the targeting sequence) appropriate for use with AsCpf1 in order to target a specific segment of genomic ...
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1k views

What is preliminary work in a biological investigation?

Here is an example of preliminary work that confuses me (from an A level Biology exam question). Please help me by providing an explanation of preliminary work in the generic sense, then use the ...
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1answer
313 views

Why is EcoRI supplied with a unique buffer when it is allegedly 100% active in universal buffers?

Thermo packages a unique buffer with EcoRI: 50 mM Tris-HCl (pH 7.5) 10 mM MgCl2 100 mM NaCl 0.02% Triton X-100 0.1 mg/mL BSA However, they also list their EcoRI enzyme as 100% active ...
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2k views

What are “primary amino acids and secondary amino acids”? Context: analysis of amino acid content using reversed-phase HPLC

In a Russian document I'm translating, an HPLC system is used to analyse the amino acid content of a substance. The detector wavelength is set at 262 nm for "secondary amino acids" and 338 nm ...
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99 views

Plasmid transformation yields only empty vectors

I have to electroporate pMAD cloned with an insert of 7.4 kb in my S. aureus isolate. When I electroporated in RN4220 I had no problems but when I put it in my isolate I just recover few colonies and ...
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46 views

How to send many samples to a lab for testing mosquito-transmitted diseases?

I am doing a project for the science fair in my school on mosquito-borne diseases in Panama. We want to collect mosquitoes from three different areas in the country to document what diseases they had, ...
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1answer
205 views

Can LSD in very small amounts increase mental ability?

Can one take a small amount of LSD(acid) and not trip but still benefit from the intended purpose? It was said the military invented it for extra sensory abilities. It has also been said it could ...
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105 views

How would you identify the independent variable in an experiment where it isn't specified? [closed]

I know that the above question is broad, but I specifically want an answer in terms of the following investigation - all of question 3 (ONLY) of this paper. The independent variable, according to ...