Biochemistry and Molecular Biology

People, I know dehydration, at different severity levels, affects the body (heart rate, sweating decrease, cramps/spasms, etc), but heard a "theory" that even a slight thirst, one which the body's biochemistry may not even make you aware of, can rob the brain of water content, decreasing the memory ability. Does that make sense? (oops, while writing this I was not drinking , better drink water now.....) Thanks, People. I should add, if the ebove is true, why does our body then, not warn the brain to drink at the critical moisture loss "level"?

I ordered the wrong type of Phenol for my lab, we needed Phenol saturated with Tris and I just ordered just regular liquid phenol, so I have now brought it upon myself to sature the Phenol with Tris. I have a protocol which I will write here, after which I have a question or two. The protocol tells me to add equal volumes of 0.5 M TrisHCl pH8, mix, and take off the aqueous phase. Then, add equal volumes of 0.1 M TrisHCl pH8, mix, and take off aqueous phase. Then, add equal volumes of 0.1 M (or 0.05 M) TrisHCl pH8, mix, take off aqueous phase, and messure the pH to make sure it's around 7.6-8. My questions: 1. Should I do this in a beaker that has a stir bar in it…

In the eighties we were inundated by government advertisements predicting biological armageddon if society did not change its sexual behaviour. Today we are inundated by pornography from every source depicting sex with not a condom in sight. What has happened to Aids?

Wondering if anyone has experience of working with acid-urea PAGE; I'm trying to run one such gel but encountering problems. Main problem is the samples don't stack. On using a different kind of sample buffer (has glycerol, but not mercaptoethanol) the tracking dye (ethyl green) disappears. It either becomes colourless (reacts?) or instead of entering the gel diffuses out into the buffer (don't know which one). Any clues anyone?

Hi, I read a job description which said that a part of the job will be structural and functional studies of different proteins. Now I`m wondering which methods these studies could include. Maybe somebody who is experienced in this kind of lab work can give me some more information. Thanks

Hi! There is no explanation about mitochondrial DNA replication in my biochemistry textbooks so I searched the internet and found a few articles but I'm not sure if I understand it correctly. Can anyone help? So the heavy strand is synthesized as the leading strand and the light strand as the lagging strand? Their origins are separated on the chromosome and the heavy strand origin is in the noncoding sequences and the light strand origin is close to tRNA genes. Why? And there are RNA primers involved as well, right? Thank you!

Hello Do anyone of you know how nitric acid (HNO3) interfere on the BCA (bicinchoninic acid) assay? I'm trying to find a protein contamination (probably 1-20 ug/ml) in 15% NHO3 Cheers, OB

During my research i came across a peptide* in a research article# which is surprisingly stable to proteolytic enzymes with normal amino acids. Its an antimicrobial peptide which is resistant to the proteolytic enzymes pepsin, trypsin, chymotrypsin, proteinase K and pronase and broad pH stability. How can this be possible that these enzyme are not able to act at their specific site even though no protecting group is present. * MACQCPDAISGWTHTDYQCHGLENKMYRHVYAICMNGTQVYCRTEWGSSC # http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0031498 2012P Identification, purification and characterization of laterosporulin, a novel bacteriocin produced by Brevib…

Can studying chemistry be just as good as biochemistry for going into cancer research after university? I'm studying a chemistry degree which comprises all the main areas of chemistry in the first and second year, industrial placement in the 3rd year and a research project in year 4. I plan to take chemical engineering as an optional module throughout. Also, where can I find the most recent literature in research belonging to the forefront of their respective fields?

Hi I am trying to express a 3X-flag tagged protein that's ~82kDa (with tag) in 293T cells. After transfecting the vector, I performed a Western blot to check for expression. On the Western blot my protein expresses at a higher molecular weight of ~130kDa. I am most certain that this is my protein of interest, as I have blotted with an antibody against the flag tag, as well as an antibody against the protein of interest. I have tried expressing the protein in different cell lines, and in all 3 cell lines that I have tried, it expresses at ~130kDa. Would anyone know why the protein is expressing at almost twice its size. Or are there ways I can troubleshoot this. Please hel…

I want to identify homology between two peptides. How this can be done?

I am a msc student and want to know about Micro RNA ?

Hey guys/gals, This is my first time going to an internet forum on account of an issue in the lab. I'm no biochemist, but have decided (for some masochistic reason) that the best way to identify a particular enzyme whose activity can be measured but for which no gene has been identified, is to try to purify this enzyme "from scratch". We have an FPLC, and I've used ion-exchange and gel filtration to purify proteins, however in those cases I always knew the characteristics of those proteins (pI, cofactors, etc) and they were overexpressed. In this case, I have a sensitive assay for the activity of this "new" enzyme, however I obviously know nothing about its characteri…

Dear All! We have a serious problem with our Fluoromax (the oldest) Spectrometer. We can't join it to a new computer, because we have no "instrument disk". Have anybody this instrument disk? Or do somebody know which port adjustments it uses to communicate with the computer? The original distributor of the machine couldn't (or didn't want to) help. Thanks a lot.

I would like your opinion on a biological issue. I am analyzing the toxicity of gold nanoparticles (AuNPs) and I'm almost sure that the mechanism of toxicity of these nanoparticles is due to multiple effects very different from the effects observed by other types of nanoparticles (silver, titanium oxide, etc.). Indeed all other types of nanoparticles can release ions while AuNPs can not ionize. To definitively demonstrate this effect I want to understand whether the metal ions can cross biological membranes. In addition, I would like to understand whether gold ions can enter and/or exit from the different cellular vesicles. Thank you very much for your help, Nikolai

As a newcomer to the world of biochemistry I am finding it quite tough to pin down some of the details needed for the study that I will be doing for my dissertation. I am currently thinking that I will be using Ion exchange chromatography for this study but I am unclear how to create good testable samples from the raw and cooked food samples that I will be analysing. Any suggestions would be miraculous. Thank you for any help you can offer.

hi! I am a new memeber to this forum. I am doing PhD in molecular bilogy. My work is to generate transgenic tobacco plants and to analyse the transcript levels of the transgene at different stages of leaf development. For this, I took very young, mature and the very old leaf as senescent leaf. I extracted RNA from all the leaf samples using Trisure. But the problem is that the RNA is getting degraded in the senescent leaf samples and mature leaf samples. Initially I thought it was a problem in handling the material but even the second time extraction remains the same. Hence I am unable to decide the reason for this. I would be very thankful if some one explains me the r…

Hi, I am new to this forum and I would like to ask for some kind advice regarding sterilisation equipment. I would like to purchase a small autoclave to handle multiple tasks in a microbiology laboratory. I need a programmable device with which one can prepare culture media and sterilise small equipment and waste. I did a search on the web and I found something that would correspond to my budget: this autoclave (the programmable one). Could you please give me opinions about this steriliser? Your help will be precious. Regards, Tim

I am involved in a discussion concerning Methane on Mars...I suppose it being a hot topic on Mars at the moment. The contention is my adversary insists that the lack of detected Ethane is indicative of a non-biological source in the detected Methane signature from orbital as well as Earth based observations. He claims that ALL Methanogens produce Ethane as a by-product of metabolism, that it is more reliable then just a methane C-12 signature, that Ethane is easily detectable with the tools at our disposal, and the absence of the Ethane signature is the smoking gun in a denial of no bacteriological life on Mars. I am no Bio-Chemist, just a lowly HNC on Inorganic Ch…

I've been having this debate with my mom for ages now, and to be frank, she's really starting to annoy me, because her argument seems utterly vapid from a scientific point of view. I once made the common sense statement that it is not possible for a person to put on more weight than the net weight of their daily food consumption (in other words, if a person, ANY person, eats say 0.5 lbs of food in a single meal, the person can't gain more than 0.5 lbs as a direct result of only that 0.5 lbs of food consumed), and she keeps saying that I don't know what I'm talking about. To me this isn't even a topic worth debating, because it is a simple matter of conservation of mass, t…

Hi, I am trying to differentiate MSCs isolated from human amnion (and amniotic epithelial cells too) into adipocytes and osteoblasts. Cells were plated in 12-wells plates at a density of 25x103 /cm2 for adipogenic differentiation, and 15x103 /cm2 for osteogenic differentiation. After 3 days cells grown to confluency, and i am afraid it is too quickly. My question is: can i passage cells during differentiation? There is 18 days more, and the each well is completely overgrown. I am afraid that cells will start to detach from the bottom and cells begin to die. What should i do? Thanks a lot...

Hello everyone,I am in the need for desperate help after failing to clone a 2.3 kb insert to a 3.5kb target vector for a few months now. This is what I have done so far: 1. Run a PCR on the gene from a library (on a plasmid source) primers with restriction sites for XbaI and SpeI corporated. 2. digestion with the restriction enzymes of the very nice PCR product, and ligation to the target vector. This ligation (ratios 1:3 1:6 1:10 vector:insert) did not work no matter what I did (with and without CIP, and with a sequential cut of the vector). The target vector was verified to be linearlized 3. Assuming the PCR product does not cut efficientl…

Hi All, I am using Benzamidine sepharose beads to get rid of thrombin after GST tag cleavage. Afer I added the beads to the protein solution which contains Thrombin I took samples from the beads and the supernatant to check the purity of my protein in SDS and found that most of my protein bound to the beads. Any one have an aidea how to avoid this problem. Regards,

Blood was added to 12 chemicals. I predicted that the chemicals with a higher molecular weight would lyse slower than those of a smaller molecular weight. My results disproved that. The numbers where all over the place. What factor allows you to predict what will lyse quicky and what will lyse slowly. Please explain in detail. Thank you

Does anyone know if there are any downsides to using UV spectrophotometry to determine the concentration of a purified protein? The only one I can really think of is that it would also measure any protein impurities the sample might contain in addition to the desired protein and add them into the final concentration it gives. Does anyone know if that is indeed a problem, and if there are any others?