Questions tagged [molecular-biology]

The study of the molecular processes underlying life.

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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 ...
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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 ...
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Can Cas13 be used with multiple crRNAs in the same reaction?

CRISPR-Cas13 equipped with crRNA (complementary to transcripts of interest) can be designed to target ssRNA transcripts in cells. Upon successful crRNA and ssRNA binding, a fluorescent domain on ...
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25 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 ...
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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.
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1answer
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Difference Junk DNA and Pseudogenes

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 ...
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DNA sequencing CCR5-Δ32 [closed]

DNA sequencing is a viable method of mutation detection. Describe what you would expect to see in a sequence trace for each of the following scenarios. Your answer to each should refer to the sequence ...
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14 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 ...
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1answer
79 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?
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3answers
29k 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 ...
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1answer
76 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 ...
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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 ...
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2answers
58 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 ...
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1answer
55 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 ...
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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 ...
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1answer
28k 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 ...
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1answer
32 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 ...
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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 ...
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1answer
42 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 ...
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36 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 ...
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1answer
27 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, ...
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Buffer Components affect DNA methylation patterns?

I am using this buffer to preserve blood cells for long term storage. The buffer contains the following: 100 mM Tris, 100 mM EDTA, 10 mM NaCl, and 0.5% SDS. From the literature it seems that EDTA ...
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18 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, ...
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2answers
160 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 ...
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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 ...
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2answers
82 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 ...
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142 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 ...
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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 ...
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2answers
816 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 ...
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1answer
50 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 ...
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140 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: ...
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1answer
41 views

Ligation without purifying insert

I am planning to insert a 45 bp sequence in a vector. After restricting my insert to create compatible sticky ends, I am finding no way to clean it up. Is there any way for cleaning this fragment ...
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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 ...
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3answers
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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 ...
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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 ...
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25 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 ...
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1answer
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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 ...
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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 ...
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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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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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3answers
542 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 ...
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633 views

Are all genes transcribed in differentiated cells?

My textbook tells me that it’s specific transcription factors that allow for a different set of genes to be expressed in different cells (differential gene expression). My book gives the example of ...
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In HIV-1, what produces Tat?

The Trans-activator of transcription (Tat) plays a crucial role in regulating the transcription process of HIV-1. But which state of the Long Terminal Repeat (LTR) produces Tat? Is it the "...
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Do molecular motors have a life time?

Most of the enzymes have a certain lifetime. I want to know that do molecular motors have a certain lifetime after which they degenerate? Any reference will be appreciated. Basically, I just want to ...
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What is the difference among biochemistry, molecular biology, molecular genetics and structural biology?

I have never heard of straigthforward definitions of these fields in my college lectures, and the Internet searches were not very helpful. However, from what I have learned at different subjects, this ...
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Why magnesium ion is needed for activity of G-proteins?

I was studying about G-protein coupled signaling sysytem, somewhere they have mentioned about need of Mg$^{2+}$ for acticty of G-protein and related it to increase of cyclic AMP production. On further ...