The study of the molecular processes of the nucleus and cell function.

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TAA- Tumor associated antigen [duplicate]

An approach to find Tumor associated antigens is based on transfection of expression library made from cDNA into cells expressing desired MHC haplotypes. Can someone please explain what this line ...
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1answer
38 views

Why can't NMR be used on large RNA molecules?

While reading my Molecular Bio textbook, I came across a sentence that stated that NMR cannot be used on large RNA molecules to determine their structure. Why is this? Is it because RNA is single ...
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59 views

Protein Isolation from mammalian cells

What non-SDS buffer can I use to isolate protein from mammalian cells? The protein is intended for testing electron transport chain complexes.
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1answer
56 views

Immunodominant Peptide

Can someone please explain me the concept of Immunodominant peptide in simple language?? I did read the wiki article but did not understand it clearly. Please help! (I have not studied biology since ...
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1answer
39 views

Localization of B and T cell

What does localization of B-Cell mean?? "Localization of B and T cell in allergens may not coincide". What does this statement mean? (I have not studied biology since last 8 years and now I am going ...
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1answer
106 views

What is the expected effect of pH on the activity of a fungal pectinase?

I am working on an enzyme assay for a fungal pectinase.I assayed the enzyme in different buffers from pH 1-12.5 However,the enzyme has good activities starting from pH1-10.5. Is it possible to have ...
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1answer
52 views

Propensity Score for amino acid

What is the meaning of propensity score of amino acid? How is it calculated? (I have not studied biology since last 8 years and now I am going through it because I need it for my research. So if ...
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1answer
31 views

How to identify the genes that distal enhancers pair?

I am writing a project proposal and I have to talk about this problem: how to identify the genes that distal enhancers pair? I am really new to this topic and I don't know what it is all about. I ...
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1answer
206 views

What is a protective epitope?

What is a protective epitope? An epitope is basically a part of antigen. So does it mean that when the epitope combines with an antibody, it helps in the functioning of the antibody instead of going ...
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41 views

What does the term 'epitope mapping' mean? [closed]

Epitope mapping means identifying the binding site of antibodies on the target antigen. This means that the site to be identified is part of the antigen and not antibody, am I right?
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2answers
221 views

Realtime PCR plate cleaning

Have anyone used realtime PCR, is that the plate for realtime PCR is one-time using or not ? Otherwise how to clean the plate after reaction to prevent wrong result in next time using ?
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1answer
126 views

Does biotin affect downstream experiments, such as RT-qPCR?

I have two biotins--one of which is binding my RNA with cleavable bonds, and the other with irreversible bonds. Does biotin have an effect if it keeps its bonds with RNA? If it does, why is this the ...
3
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1answer
49 views

How do you express and detect GLP-1 receptors?

I am currently working with a peptide which is an analogue for glp-1, but during invitro studies am not able to detect for the presence of GLP1- receptors. The cell line used is Min-6. How do I detect ...
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1answer
64 views

What regulates the timing of the motion of molecular machines during DNA Replication?

This question is about this video I found on Youtube. I just want to know what is the mechanism which regulates the timing of motion of the parts of these molecular machines. I know that those big ...
2
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1answer
35 views

What is the biding site code recognized by the parts of the spliceosome

Another question about another Youtube video. At 0:50, the splicing process begins to remove the non-coding section of the DNA (intron), so the different parts of the spliceosome attach to the borders ...
2
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1answer
56 views

Why do oncogenes show genetic dominance?

As we know that tumor suppressor gene causes cancer only when both the alleles are recessive in nature.But in case of oncogenes if only one allele is dominant it can cause cancer.Why in case of ...
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4answers
104 views

determine longest poly-purine tract

how to determine/ find the longest poly-purine tract in any genome and this needs to be on the E. coli genome . is it to figure out the polypurine tract and then figure out the longest chain ? or is ...
3
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1answer
124 views

Consumption of NAD+ in glycolysis

Out of 10 steps in glycolysis, only one reaction- Glyceraldehyde 3-phosphate (G3P) to 1,3-bisphosphoglycerate (PGP), uses NAD+ and thereby producing NADH. Furthermore, this very step is solely ...
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1answer
92 views

Selection on linked loci in a diploid population

Let’s consider two linked loci $A$ and $B$ that are both bi-allelic. In consequence, we have four different possible haplotypes $A_1B_1$, $A_1B_2$, $A_2B_1$, $A_2B_2$, which frequencies are $X_1$, ...
3
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2answers
336 views

How are DNA segments selected in PCR?

I understand that in PCR we're able to amplify only selected portions of the DNA... however despite reading it from multiple sources, I cannot figure out how this selection actually takes place. I ...
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1answer
318 views

Why does the pET- expression vector contain a LacI gene additionally to the one in the genome?

The pET plasmid is used for protein expression with T7 promotor in expression strains, such as E.coli BL21(DE3) It contains a lacI gene which codes for the lac repressor protein, a protein of ...
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1answer
290 views

Can I heat Trizol?

I wonder if I can heat Trizol reagent for 30 min 65C. The goal is to disrupt protein-RNA complex while inhibiting nucleases. (I can't use RNasin cause it's inactivated in 65C, and can't use RVC cause ...
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4answers
143 views

Theoretically, what technique would one use to modify a virus so that it only affected a subset of the population?

I'm writing a novel and i would like to know some of the equipment and techniques involved with modifying a virus. Is it feasible for a virus to be engineered to only affect certain people? It ...
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1answer
106 views

No digested product bands, but markers are visible. What could be the reasons?

I had to digest my insert containing plasmid and another vector into which my insert has to be ligated, each with BamHI and NotI. Upon digestion, I ran the gel to check for results. The digestion ...
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1answer
91 views

The mechanism of mechanoreception?

I am interested in knowing the molecular mechanism behind mechanoreception/mechanotransduction (i.e. mechanism behind receptor potential generation on mechanical stimulation). I know that most ...
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3answers
105 views

Hebbian theory “fire together” clarification

Donald Hebb states it as follows: "Let us assume that the persistence or repetition of a reverberatory activity (or "trace") tends to induce lasting cellular changes that add to its stability.… ...
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2answers
91 views

What are some atypical examples of positive transcriptional cooperativity?

Cooperativity in gene expression is an important feature of many regulatory networks. Described using the Hill function, the most common example is a transcription factor (TF) that when bound to its ...
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161 views

High frequency human genetic oscillators?

The most well studied genetic oscillators in human genomes are involved in regulating the circadian clock (which operates on an approximately 24-hour cycle) and cell cycle activity (with single cycles ...
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1answer
716 views

RNeasy Mini Kit low 260/230 ratio — can I purify this RNA for further use?

I used Qiagen's RNeasy Mini Kit to isolate RNA from 5*10^5 C28/I2 (immortalized human chondrocytes). However, my yield is low (~25 ng/ul), but my 260/280 ratio is great (~2.3), and my 260/230 ratio is ...
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1answer
1k views

Lyonization and X-linked disorders?

Lyonization or X-chromosome inactivation is the conversion of all but one, X-chromosomes in Females into non-coding heterochromatin (i.e. deactivated) leading to the formation of one or more Barr ...
3
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1answer
120 views

Optimization of annealing temperature

I am trying to optimize annealing temperature for some primer pairs. I have tried optimization using cDNA, genomic DNA, Taq polymerase, phusion polymerase etc., but every time I am either getting ...
3
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1answer
129 views

Efficiency of plasmid DNA isolation from frozen E. coli cell cultures

Has anyone isolated plasmid DNA from frozen (at -20degrees) E. coli cell cultures (not pellets)? Has that worked and if so, with what yields? What would be the quality of the isolated plasmid DNA if ...
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0answers
40 views

Assembling DNA fragments with ~10kb overlap in vitro

Let's say I have two fragments of bacterial DNA (~50kb in length each) that overlap on the ends by roughly ~10kb; the overlap sequences are unknown. I would like to assemble these into longer ...
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15 views

border zone of the infarcted heart

I did myocardial infarction experiments on mice and I am a newbie in this area. I need to isolate RNA and protein from the remote and the border zone. Where should I cut the heart so i can separate ...
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3answers
52 views

FRET only works for interactions between 1nm to 20nm.

FRET only works for interactions between 1nm to 20nm. How can you be sure that the interaction that you want to study isn't less than 1 nm/greater than 20nm apart?
2
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3answers
118 views

What equipment would one use to modify a virus? [closed]

Would anyone be so kind as to give me a few examples of the equipment involved when modifying a virus? Otherwise my novel may end up reading Eva entered the lab and modified a virus. Not much back ...
7
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1answer
746 views

How tolerant are ants to cold?

There was a trail of what are commonly known as sugar ants (small, brown, hyperactive) in my kitchen. Three of them walked onto an ice tray placed in their path. They only walked a short distance on ...
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1answer
5k views

Why is ATP the preferred choice for energy carriers?

Why is ATP the most prevalent form of chemical energy storage and utilization in most cells?
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1answer
142 views

What are the lifetimes of cellular components on organelle or molecular level?

I was thinking that even though I know how generally the cell works, I don't really have a feeling of how volatile it is. I want to know what is the lifetime/turnover rate of different constituents of ...
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1answer
2k views

Difference in length of Okazaki fragments

The length of Okazaki fragments in the lagging strand is about 100-200 nucleotides in eukaryotes and about 1000-2000 nucleotides in prokaryotes. What (molecular mechanism, enzyme type ) ...
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1answer
63 views

difference between ischemia and oxygen-glucose deprived medium

Ischemia is roughly defined as insufficient blood flow to a specific region of the body and in the literature it is generally considered as causing oxygen and glucose deprivation in the tissue and ...
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2answers
8k views
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1answer
484 views

Why Isolated, recombinant plasmid DNA without any restriction is often detected in agarose gel electrophoresis as three DNA bands?

I don't understand why three bands are found without any restriction digest. Please answer me as soon as possible. Thank you
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2answers
355 views

Single stranded DNA in gel electrophoresis

From http://www.nfstc.org/pdi/Subject05/pdi_s05_m01_01.htm : ... The separation medium contains a denaturant in order that the electrophoresis is conducted on single-stranded DNA fragments. ...
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1answer
224 views

Are there any organisms that lack ATP synthase?

ATP synthase is used by cells to synthesise ATP from ADP using energy from a proton gradient. Depending on which sites I look at, this is either a universal feature of living cells, or it's "almost ...
4
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2answers
118 views

A photosynthesizing mouse?

N. Shubin's Your Inner Fish makes the point several times that there is a lot of functional similarity between some seemingly remote gene cousins. If that needed reinforcing we have the spider-goat, ...
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1answer
30 views

Property of E.coli harboring F element

From Genetics by Ursula Goodenough E.coli harboring an F element are endowed with a number of phenotypic traits : 1.They are sensitive to infection by ssRNA phages and certain ssDNA phages. ...
3
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1answer
308 views

What is “bacto” peptone?

Standard recipes for yeast medium often include "bacto-peptone". Is this the same as bacteriological peptone? Is there an authoritative source that spells it out?
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1answer
79 views

How was Restriction Site of EcoRI sequenced?

The sequence of restriction site of EcoRI - GAATTC was identified in the early 1970s, before Sanger Sequencing was invented.(1977) How was the restriction site of EcoRI sequenced ?