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Questions tagged [microbiology]

Microbiology is the study of extremely small organisms. This includes organisms like bacteria, fungi, protozoa, and viruses.

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How do I homogenise a small pellet of 10 to 50 cells within less than 50 µL?

I have a problem with declumping/ homogenising bacterial cells in small volumes (10 to 50 µL). I know that I can get all of my cells out of the tube, but they are still stuck together and won't form ...
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Pits, symplastic or apoplastic pathway?

After water has moved through the endodermis through the Casparian Strip, water continues to move down the water potential gradient into the xylem vessels through the pits, is movement through the ...
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DNA replication in $ E.coli $

$ E.coli $ has circular DNA which I guess implies one strand forms the outer circle and the other the inner one. So, is there a way to know if the replicated DNA forms the outer or inner circle? In ...
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Virulence Factors of Francisella tularensis

After completing research on the virulence factors of Francisella tularensis, I was wondering about a few specific structures/toxin and whether these are virulence factors of Francisella tularensis or ...
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Why do bulls-eye rashes look like they do?

People infected with Lyme Disease often present with an erythema migrans ("migrating redness") rash. Most often, these rashes are in the shape of a bulls-eye. Rash image. Presumably, this is a ...
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How is Pseudomonas aeruginosa diagnosed?

I know that P. aeruginosa is cultured on an agar plate, but which media or assays make it distinct from other Gram-negative bacteria?
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Could a strong magnet field repel the body before damaging it?

Could a magnetic field be strong enough to damage the body or erase the brain? Blood is slightly diamagnetic, so if the field was strong enough, could it repel a body evenly? Could a diamagnetic ...
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Is an uninoculated control (slant) catalase positive or negative?

The catalase test is a laboratory test utilized in identifying organisms which produce the enzyme catalase. Is an uninoculated control (slant test only) catalase positive or negative? I am assuming ...
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What concentration of hydrogen peroxide kills mold?

There are numerous articles online which claim that household 3% hydrogen peroxide can kill mold growing on household surfaces, yet I haven't managed to find scientific studies that show that. My ...
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Question Concerning Adenovirus

The question is "A 5-year-old girl arrives at her pediatrician's office with very red bloodshot eyes and a thick, yellow, and crusty discharge. Her eyes are itchy and burning. The doctor prescribes ...
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fimbriae under AFM

Can any one,please, recommend a protocol for watching bacteria with fimbriae under atomic force microscope? I have tried a lot but always there were no fimbriae i don't know why.
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In my DNA sequence for one sampling site there're W's; Y's; R's and K's?

I also just experienced the same thing with my DNA sequences, there are w's, Y', R', s' and k'. This is the very first time I've seen this. I am used to N but not these ones. Please kindly assist with ...
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when you are to non-culturally detect the presence of E. coli in the soil from a cow pasture?

You are to non-culturally detect the presence of E. coli in the soil from a cow pasture. You do this by extracting the total DNA from a sample of the soil and PCR amplifying with E. coli-specific ...
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Is there a consensus on the best Machine Learning model for Antimicrobial Resistance (AMR) prediction?

Prediction of bacterial resistance/susceptibility to antimicrobials (from genotypic data) using Machine Learning methods is a problem that has started receiving interest in recent years. The ...
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Operon Repressors and activators

I know that the repressor when it binds to inducer it cannot bind to the operator and transcription goes on. As for the activator, it is made either active or inactive based on the environment and ...
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If a bacterium had a protein on its surface that humans also have, would it cause an autoimmune disease?

Suppose that a bacterium happened to have a protein on its surface. This protein can also be found in the human body. If this bacterium were to then infect a human with an otherwise normal immune ...
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Is it possible to identify this microscopic particle?

So I was playing amateur scientist with my 11 year old. This photograph is from rainwater in a bird-feeding bowl in south England, at 300x. It looks biological, but I have no idea what this is. Is ...
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What do the text annotations in an electron micrograph mean?

I saw a photograph taken from an electron microscope, with some text. I want to know what is the meaning of these numbers and letters? Thank you! Regards.
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synthesis of zn nanoparticle

Sir the protocol I followed where it has been written... 1st using lactobacillus in Mrs media (50 ml in 250 ml conical)..we allowed to incubate for 24 hrs then added 0.1M znSO4 (50ml) and 0.4 M NaOH(...
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What makes an E.coli an E.coli, genotype or phenotype?

According to this paper, among 61 strains of E. coli they studied only 6% of the genes are common in all. Which means that the overwhelming majority of the genes are not shared. And wikipedia ...
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Why doesn't alum coagulate my cyanobacteria?

My collected rainwater has a pronounced blue-green tint which I believe to be due to the presence of cyanobacteria. I have been trying to remove the cyanobacteria using aluminium sulphate, but it ...
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1answer
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Why are tardigrades so rare?

If tardigrades are so resilient and nearly immortal, why are they so rare when looking at samples of a pond or lake, where tardigrades should thrive? I've met people who've been studying protozoa and ...
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Is it possible to remove cyanobacteria from rainwater without killing it?

My collected rainwater has a pronounced blue-green tint. I presume that this is due to the presence of Microcystis or another planktonic cyanobacterium. Is there a way to remove the cyanobacteria from ...
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How is the right amount of nucleotides synthesised during homologous recombination?

I'm reading about homologous recombination in the context of double-strand break repair. It seems like the trick is that around the break, homologous recombination uses a template duplex to generate ...
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Why some eggs are bile stained?

Why eggs of some helminths( Diphyllobothrium latum, Trichuris trichiura, Ascaris lumbricoides etc) are stained with bile while eggs of other helminths( Hymenolepis nana, Enterobius vermicularis etc.) ...
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qPCR: Accounting for different sample mass when interpreting and comparing Ct

I'm trying to use qPCR to quantify the amount of a specific bacteria species in patient sputum, but I don't really have the option to use consistent quantities of sputum to elute DNA from. The qPCR ...
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what is the characterization of mutant bacteria and how is it done? [closed]

I have a task to characterize protease producing bacterial mutants but I have failed to understand what it is and how it is done
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Volvox Cellular Reintegration

A couple of days ago, I answered this question over on worldbuilding.SE with some information about volvoxes, and commenter Liam Proven pointed out that one of the claims I made was dubious. I had ...
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particles in spirulina medium

Can any one suggest what are this particles in my spirulina growing medium? PH is between 10 and 11 and the medium is few months old. It turned green and stays green color even after I filter ...
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Trying to find the right plasmid expression vector for e. coli c600

I am very new to the concept of gene cloning and transformation. I am trying transfer the arenite oxidase gene cluster (9kb in length) to E. coli strain C600. I want the E. coli strain to express this ...
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can a naegleria fowleri amobea live in a bottle of water?

I want to know if this amoeba can live in a bottle of water that has been storaged for 10 years? I brought a bottle of water from the town of Lourdes in France 10 years ago. they sell the bottles of ...
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What happens to Bacterial Cells stored at 4 degrees?

4C is when water is most dense and is not so low as to cause ice crystal formation. For short term storage bacterial cultures are often simply kept in a fridge at 4C. I guess that this significantly ...
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Why do -ssRNA viruses need to do intermediate positive strand (antigenome) instead of just replicate it negative strands?

I was reading about RSV replication here https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3185921/, but i cannot understand what is the reason for making a antigenome instead of just replicate it negative ...
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Thermophilic Total plate count with PCA with Triphenyl tetrazoliumchloride as supplement

Hello I'm am a fourth year microbiology analyst and I'm busy with finishing my final internship. During my final internship I have to complete a own assignment. the assignment I got was to find out if ...
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How does the accumulation of cyclic AMP lead to edema?

The antrax toxin is made up of three fractions. Protective antigen factor,edema factor and lethal factor. Protective antigen factor binds to the receptors of the host cell surface and facilitates the ...
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Killing microorganisms on agar plates?

If I grow microorganisms on agar plates and I expose them to UV light. How exactly will I know that the microorganisms have been killed? I was watching a video that showed spots in the petri dish ...
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Is it possible to see the microbes on your hand without using UV light or a microscope?

I know that black light (UV) is often used to see the microbes (colloquially referred to as germs) on people's hands but is there any way by which we can examine the microbes on people's hands without ...
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Why can't bacteriophages survive inside the human body thus negating the possibility of using them against bacteria?

I read about the therapeutic uses of bacteriophages in Pelczar's Microbiology. It was written that it is reasonable to think that bacteriophages could be used to kill pathogenic bacteria. However, the ...
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Do unique communities of bacteria form inside water storage in plants?

I assume that plants, like animals, have an ability to fight off bacteria that invade their cells (support: here and here. However, water often harbors quite a bit of bacteria in even unsuspecting ...
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We know that the hepatitis C virus can live on surfaces for at least six weeks. Maybe longer. The infectivity study ended after just six weeks; why?

Background A paper has found that the hepatitis C virus (HCV) can remain infective for at least six weeks on ordinary household surfaces. You can see the free full text, or a summary for busy ...
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A study found that the hepatitis C virus can live on surfaces for six weeks. Did they end the study before the seventh week began?

A study once found that the hepatitis C virus (HCV) can remain infective for six weeks on ordinary household surfaces. You can see the free full text, or a summary for busy clinicians. What happened ...
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What M9 stands for

Can anyone tell me what M9 stands for in M9 medium? I have tried googling but I still cannot find it.
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How does the intracellular accumulation of cyclic AMP cause edema in case of anthrax?

Edema factor is adenyl cyclase which is activated only inside the target cell. It leads to intracellular accumulation of cyclic AMP resulting in edema. How?
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E. Coli growth inhibited in Powdered Honey

I ran into problem with my method validation since the E. Coli that I've spiked into my Honey Powder sample can't grow in the media. The media I've used is Merck CCA (Chromogenic Coliform Agar). I've ...
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Why does tetracycline have such a broad spectrum of activity?

What are the structural and chemical characteristics that make tetracycline uniquely broad spectrum? I understand it acts on the A-site of the prokaryotic ribosome, but there exist many ribosome-...
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Can vaccines move from person to person?

Can someone who has been given a vaccine "infect" another person with the virus used in that vaccine? For example, let's say Bill is vaccinated against tuberculosis. If Frank is exposed to Bill, is ...
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Antigen molecular mimicry

Let us consider a situation in which the body is attacked by a microbe, and the microbe is captured by the immune system for recognition of surface antigens. The surface antigen recognized mimics one ...
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Glass petri dish to replace plastic petri dish?

I never use a glass petri dish before, but I just wonder if I can use it to replace for plastic petri dish because it can reusable. The only thing I worry is , in a Fridge's user manual, it said that ...
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How do I determine an acceptable $F_0$ value in sterilization?

Here's a sample question: The sterilization process using moist heat is used to kill B.stearothermophilus by heating to 115 degrees C and holding it for 30 mins. For B.stearthermophilus, it ...
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How Would I Isolate and Amplify a Viral Enzyme? [closed]

what procedures would I use to isolate and amplify integrase? If I am trying to study the integrase enzyme which is found in HIV how would I 1) destroy the viral capsule to release its contents. 2) ...