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Questions tagged [molecular-biology]

The study of the molecular processes underlying life.

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4
votes
2answers
102 views

How can you band wheat chromosomes using Giemsa dye?

I am working with wheat chromosomes and trying to stain the chromosomes. However, during staining with Giemsa dye chromosomes appear totally dark. I'm not sure why this might be. Anyone have any ideas?...
0
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1answer
26 views

What is ApoCas9 in the CRISPR-Cas9 system?

I am currently reading an article about a particular assay of Cas9 nucleases. In one of the experiments, they have used ApoCas9 (Apo variants of other CRISPR nucleases) as some sort of control. But ...
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0answers
44 views

plant uptake of large molecules

I have read several studies concluding that plants can indeed take up molecules with a molecular weight larger than 390 g/mol. Does this mean plants do also take up large molecules like hormones if ...
0
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1answer
46 views

Approximate Cell Doubling Time?

If I know it takes 12 min to occur in mitotic fibroblast cells and I count there are 32 dividing cells in the microscope slide out of a total population of 32034 cells, how do I calculate the ...
0
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1answer
43 views

Non-coding DNA as a protection to deleterious mutations

We know that most part of our genome (at least 75 percent) is non-coding DNA. Can it be a way to protect the organism from mutations in important genes, such as the ones which control cellular cycle, ...
3
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1answer
98 views

What Ultimately Controls DNA Transcription?

Transcription of DNA and further splicing of mRNA is regulated by various transcription factors, small nuclear RNAs and so on; similarly such related mechanisms as transposition of transposons. All ...
-2
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2answers
111 views

Why isn't the human zygote considered a human life how is a living anatomically modern human defined biologically? [closed]

It has 46 chromosomes by default when healthy(Differences almost always are pathological) and has almost every biological functions, processes a Newborn or and Adult person has. It even invades ...
0
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0answers
21 views

How can I improve efficiency of Ecoli transformation?

I am an intern in biology institute. I have a 17.3kbp plasmid need to transform to Ecoli. But I have tried many time but have no or very few colony on LB plate. I know large plasmid have less ...
3
votes
1answer
52 views

Can denatured GFP show fluorescence?

GFP ( green fluorescent protein) can show green fluorescence. And its fluorescence is due to the tri peptide chromophore which is given in below I was wondering, can we observe fluorescence, if we ...
0
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0answers
29 views

How to troubleshoot in vitro formaldehyde fixation for nucleosomes?

For an experiment, I am trying to fix the mononucleosomes (100ng) using formaldehyde as crosslinking agent in HEPES buffer. I have been using 2% formaldehyde in a reaction buffer containing 1mM EDTA, ...
0
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1answer
32 views

Does anyone know a good pancreatic-cancer metastasis cell line?

Researching about pancreatic cancer. We have mostly "main-tumor" cell lines in our lab, and I´m currently looking for cell lines originating from metastases (liver, lung, etc.). Does anyone know a ...
1
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0answers
20 views

Which animals don't have pheromones?

Which animals are known to not have pheromones besides humans? I can't find any research on this. There are examples of every class that uses pheromones. However nobody seems to answer conclusively ...
0
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1answer
34 views

How to do desalt reaction by passage through a Micro Bio-spin 6 column?

I want to perform the bisulfite sequencing on rRNA to detect the 5-mC. I followed this protocol • DNA-free™ DNA Removal Kit (Invitrogen) • Purified RNA, Treat RNA according to manufacturer's ...
6
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2answers
27k views

Why is the DNA helix anti-parallel? [duplicate]

Why is it that DNA strands are running in anti-parallel fashion? Given the chemical base-pairing, they could have been parallel just as well.
-2
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1answer
46 views

Difference Junk DNA and Pseudogenes [duplicate]

1-Are Pseudogenes and Junk DNA both Non-Coding DNA or they are different entity? How much Pseudogenes & Junk DNA do we have respectively? 2-I read that Non-Coding DNA has functions, my question ...
0
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0answers
15 views

Holder for 75 mm x 25 mm glass slides that can handle vibration

Hello Biology Stack Exchange, I have an application where I have cells on a glass slide (dimensions: standard 75 mm length x 25 mm width x 1 mm thick). I want to vibrate/shake the cells rapidly ...
2
votes
1answer
90 views

How to generate protein graphics for illustrating articles?

The structure of insulin shown below appears in a Wikipedia entry. What software was (or can be) used to create pictures of this type?
184
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3answers
30k views

Why are so few foods blue?

Although blue foods exist, they're rare enough compared to other foods for food preparers to use blue plasters as a convention. The natural colour of a given food is due to pigments that have some ...
-4
votes
1answer
83 views

Does this article call into question the theory of evolution?

https://www.quantamagazine.org/neutral-theory-of-evolution-challenged-by-evidence-for-dna-selection-20181108/ The article above challenges how mutations work in evolution. Does this disprove the ...
0
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0answers
29 views

Why do people use J2 viruses for macrophage immortalization?

I've been trying to figure out how to go about immortalizing some primary alveolar macrophages harvested from mice. What I am seeing in the literature is that it seems like people have been using a ...
1
vote
2answers
71 views

What is the subcellular location of synthesis of non-essential amino-acids?

What is location of non-essential amino acids synthesis in a cell? Is it some specific organelle? And what is the gene driver behind this? I thought the whole point of DNA is coding for how to ...
1
vote
1answer
61 views

What is the role of CRISPR-dCas9 in gRNA-dCas9 transcription regulator complexes?

In this paper1, I read that mutant versions of Cas proteins such as a deactivated Cas9 (dCas9) are used alongside a guide-RNA (gRNA) to form variants of CRISPR tool that can function as transcription ...
0
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0answers
26 views

Biochemistry of pleasure of/desire for physical exercise in mammalians and humans?

Are there some known biochemical mechanisms, that induces desire for/pleasure of physical exercise in mammalians and humans? I have heard, that horses can not live without physical exercise and they ...
3
votes
1answer
31k views

Catabolic and Anabolic Reactions

How do we differenciate between catabolic and anabolic reactions? According to my researches; Catabolic Reactions Catabolic reactions (also called “catabolism”) break down larger, more complex ...
3
votes
1answer
36 views

What buffer should I choose for IEX chromatography for purifying IgY

I will use ion exchange chromatography with an anion exchange column to purify chicken IgY. Prior to this I did dialysis to remove salts from previous purification steps, is it possible after this ...
1
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0answers
21 views

Chemical inhibition of fertilization in plants

Are there any chemical compounds that inhibit fertilization in plants after gametogenesis? Simply put, I am talking about spermicide or emergency contraception for plants. Specifically, I am ...
1
vote
1answer
45 views

Application of molecular dynamics simulation (or alternatives) for the full pathways of protein interactions?

If one would like to control the biological system (e.g. to treat disease or aging/senescence) then one should introduce the drugs in the system, that initiate complex protein interaction pathways ...
1
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0answers
48 views

ATP and Muscle Contraction

I have a question regarding how molecular interactions manifest in physical actions - such as hanging from a bar. To the best of my understanding, when it comes to the contraction of muscles, ATP is ...
0
votes
1answer
32 views

Can I use a basic compound microscope to analyze the ploidy of plant chromosomes?

So, I'm not really any kind of trained botanist. But I do have two things: some dandelion seeds from France, and, collecting dust in my garage along with related accessories, this thing. Normally, ...
2
votes
2answers
226 views

What is the meaning of “Rb is in the active state”?

I am reading about cyclins, cdks and Rb (Retinoblastoma) and some of the terminology is not clear to me. I understand that when CDK phosphorylates Rb, it disconnects from E2F, and E2F can act as a ...
1
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0answers
32 views

How do receptors lose their sensitivity?

Recently, I learned that one of the causes of Type II diabetes is that insulin receptors on cell surfaces lose their sensitivity due to long-term high exposure to insulin (which occurs as a result of ...
3
votes
2answers
86 views

Does the lack of “mirror life” tell us anything about abiogenesis?

My (extremely rudimentary) understanding of Biology is that many of the building blocks of life are chiral and that life on earth is entirely made up molecules with the same chirality. Does this ...
0
votes
1answer
151 views

How are single-stranded binding proteins removed from the lagging strand during DNA replication?

The lagging strand, downstream of the Okazaki fragment, is covered in single-stranded binding proteins (SSBPs) during DNA replication. What is the mechanism which ensures that SSBPs are removed from ...
0
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0answers
10 views

What is the relationship between Ca- and Na-ions and mucins and why?

According to Wikipedia https://en.wikipedia.org/wiki/Mucin#Secretion mucins (Proteins that form mucus) obtain viscoelastic properties by the Exchange of sodium and Calcium Ions. What is Happening ...
1
vote
2answers
951 views

Are my plasmids single-stranded?

Hi, in this agarose gel photo (70 volts, 3.5uL Gel Red in 30ml of TBE, 1% Agarose, 1 hour run), I've checked the digestion of a large plasmid (15Kbp, one cut site). The theory says that the digested ...
0
votes
1answer
51 views

Is the lac operon repressed in the presence of both glucose and lactose?

In the presence of both sugars (glucose and lactose) will there be repression of the lac operon completely? I know that more glucose means less cAMP --> less CAP --> less positive regulation, and ...
4
votes
2answers
162 views

Why are dietary recommendations for methionine consumption combined with cysteine?

I want to understand the amino acids missing in certain vegetables. I looked up the US recommendations for amino acids (source: wikipedia). I don’t understand why they pair Methionine + Cysteine: ...
0
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0answers
19 views

How are multiples transmembrane proteins translocated or embedded in the membrane?

This image is in the textbook, Molecular Biology of the Cell. I understand why the start and stop transfer sequences must alternate, but why is there 2 consecutive start transfer sequences at the N ...
3
votes
3answers
298 views

What does the gene name “lexA” stand for?

It is an important gene expressed in E. coli that represses the SOS response and also the expression of lambda lytic phase genes. UV light and damage to DNA is responsible for its breakdown and hence ...
0
votes
0answers
12 views

What is the typical concentration of Calcineurin (PP2B) in CA1 dendritic spines?

I am trying to find the concentration of CaN (PP2B) in dendritic spines, there is a computational model (doi:10.1073/pnas.0804672105) that uses the quantity of 1uM in the dendritic spine. I think this ...
0
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0answers
26 views

Could Wobble Base Pairing ultimately yield an amino acid that was originally uncalled for or not expected?

How does the cell choose which amino acid to attach to tRNA when there is wobble base pairing involved (not the other way around)? Consider the example below. For the purpose of this question I'm ...
2
votes
1answer
46 views

What is the difference between DNA vs RNA Editing in the context of gene therapy?

As a someone with beginner knowledge on biology, I have come across the terms "RNA editing". Take this paper for example : RNA Editing with CRISPR-Cas13 From my understanding, DNA -> RNA -> Proteins ...
0
votes
1answer
47 views

Why do NK cells not destroy bacteria, even though bacteria don't have MHC-I?

Part of the function of NK cells is to destroy cells that are unable to bind their KIR receptors. Or in other words, cells that don't express MHC class I. This is why they can kill MHC supressed ...
0
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1answer
44 views

Dna based question [duplicate]

We know that dna is an acid which is elaborated by deoxyribo nucleic acid.It has 4 nucleo bases.Now,the question arises, why dna has no uracil base?
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0answers
22 views

Can a lentivirus expressed protein that is undetectable by western blot be detected by BioID?

Cloned a single herpesviral gene into pCDH-EF!-GFP and see phenotypic effect on cells of interest and viral gene transcripts BUT unable to detect ANY protein using HRP boosted western blot. Even with ...
0
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0answers
32 views

Need help in identifying and understanding the origin of an expression variant

We usually denote the origin of a mutation as either somatic or germline. This information is usually available in certain databases such as CIVIC, ClinVar, COSMIC etc. But when we come to variants ...
1
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0answers
34 views

How to map the N6-dimethyladenosine by primer extension?

I am trying to map N6-dimethyladenosine on rRNA using primer extension (low dNTPs assay) method. But i am not able to detect map my position. I went through some articles they mentioned like they ...
0
votes
0answers
23 views

Insight on HPV vaccine to prevent/control reactivation of latent infections in those already infected

Some women experience reactivation of HPV infection in their 50's due to weakened immune system and weakened immune memory. Is it outside the realm of possibility that giving the HPV vaccine to those ...
1
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0answers
48 views

Protein misfolding [closed]

Protein misfolding is usually prevented by molecular chaperons. Rarely, the chaperons are not able to prevent the misfolding as a result of which the infectous molecules called prions will form. My ...
2
votes
3answers
570 views

Getting PCR amplification at annealing higher than Tm!

I am amplifying a gene where in a gradient pcr i am getting amplification at an annealing temperature about 5 degrees (67) higher than Tm (62.5)? What is wrong here? Also, I am getting a very strong ...