Biochemistry and Molecular Biology

I’m doing a study to determine the rate of covalent modification, also known as kinact/Ki. From the literature, I see that it is determined by plotting percent occupancy over time (DOI: 10.1177/1087057116671509). I ran a 3 pt (8 compounds) fluorescent assay over 180 minute and normalized the data to the blank at time t and the final positive control. This activity vs time was converted to percent occupancy over time with a typical (1-value)*100. The graphs this generates are not consistent with what is expected from the literature, and I’m curious as to whether I have done something incorrectly, or if these compounds are not, in fact, covalent; I’m not sure how likely tha…

I need to measure the Lycopene production of E.coli strain on different mediums. I have used Acetone, to extract Lycopene from bacteria, as described in literature. But when I started to measure the absorbance (470 nm) using 96-well microplates, some of the acetone would evaporate and ruin my results (even with the lid on). Most of the literature that i have read uses HPLC to evaluate production, but some have used absorbance as well, but they dont specify their methods in great detail. Can anyone help me by give me some tips, how could i slow down the evaporation. Or maybe i should use a different solvent? Thank you in advance, a desperat…

Proteins don't form perfect crystals, why?

Hi guys, so I started my PCR last week, I'm analysing capsicum species using RAPD markers, but I'm a little confuse of how should I procede with my PCR. First of all, my professor said that I couldn't make the mix all at once and then distribute to micro tubes with my DNA samples, she said that I should prepare the mix separately. Well that's quite annoying, because I have a lot of samples and I must amplify each primer 3 times. Is it really necessary prepare the mix for each sample? Second, for my project my professor selected 20 primers to analyze the polimorphism and etc. will each primer have its own temperature of annealing, desnaturation etc. or shoul…

Good day, I need an IGF-1 Amino acid sequence figure with 3 letters abbreviations of amino acids. i.e: Cys for cysteine for my Master thesis. I have searched the Internet for a scientific paper with this type of figure a long time, but I have not found it. Please help. Thanks in advance

I would like to visualise myosin II while live imaging, without tagging myosin II with a flourophore. Is there a stain/dye that can be used for myosin II in live cells? Thanks!

These is md and mcf cells are in the flask of the medium, does anyone know why they came in this way?

Why would cell division be a mean that prolongs life of a unicellular? In many encyclopedias you can read life is mortal due to multiple reasons (mutations in nuclear and mitochondrial DNA, DNA methylation, shortening of telomeres, accumulation of waste material and free radicals). All those negative impacts are accumulated in a cell mass that is to divide, so from my standpoint, division would be just splitting in two material that would be equally close to death in the life path, as it was before the division. I do not see what is rejuvenating in cell division, as we here talk about mitosis of unicellulars (almost no gene recombination to revitalize the gene p…

Hello I need some biochemical knoweldge 1. Day ago, during accident i left my Natural Aloe Vera juice in room temperature for about 20 hours. Keeping Aloe Vera juice for long in room temperature destroys its organic power. Smell become a more acidic, like milk in just begging of fermentantion, can you confirm or deny from my provided information that Aloe vera juice is still drinkable or not ? i provide image of composition. Thank You Very Much. And please forgive if i posted in wrong category

I'm by no means a molecular biologist so please excuse any mistakes. I'm interested in agrobacterium-mediated transformation of a plant using the pNOV2819 plasmid (pic below) which uses the pmi selectable marker. I read a paper where its efficacy in transforming almonds was tested (https://www.ncbi.nlm.nih.gov/pubmed/16534597). However, no new gene was inserted into the plasmid so the transformed plants only contained the selectable marker (and promoter/terminator). I wondered if a new gene was inserted (for example at the AscI restriction site) how the selection would work in agrobacterium and the plant in terms of growth on a mannose medium and PCR/Southern blottin…

Forgive the basic question, I'm not a biochemist but am interested in understanding the below: LOX is said to be key for interlinking collagen & elastin. At the same time, I've seen it said that Cu1 supplements are more bioavailable than Cu2 supplements, due to Cu1, having 28 electrons & so an electron to donate, which it then loses within the cell after passing through the cellular membrane. Thus I've read the Cu1 is a functional copper. However, I note here: https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/lysyl-oxidase that: "LOX needs two cofactors, Cu2+ and a unique covalently integrated organic cofactor id…

I've a knew job in a cheese factory that I will be starting in less than two weeks. It's been 3 years since I graduated so I'm a little rusty. All I know so far is that it involves PCR. I'm not exactly sure what this job entails other then that, and to make matters worse there was no job spec for this role. The company is currently contracting out their PCR work, but they said they are having problems with this company, and want to start doing themselves. They've told me they're buying a new 'Bio-Rad' PCR machine and that they will be bringing in a BioRad representative to train me (and presumably other staff too). I don't really know what I'll actually be sequencing when…

Hello, I did a quiz in cytology this morning and I was asked if photosynthesis can only be performed by plants. And the answer was yes. Although also some unicell organisms can perform photosynthesis for example Euglena. Which is not a plant. How would you think about this answer. Thank you in advance

The stem-loop constructs for silencing mRNAs (~500nt) having no homology (>18nt) to other transcripts in T. brucei genome was used to generate the stem-loop constructs using primers listed above. Briefly, PCR product of part of the mRNA coding region was cloned into TOPO vector as per manufactures instruction and was used as a donor template for LR cloning with pTrypRNAiGate vector. The constructs expressing dsRNA were linearized with EcoRV and transfected into the parental cell line; the transformants were selected with 5μg/mL phleomycin. To check the silencing i tagged my protein with PTP (pC-PTP-PURO- This is the plasmid i used for tagging). I choose the same 500 nt…

Hello Guys, I'm a student who is trying to major in systems biology. My project aims to study how uncertainties propagate through a linear system of differential equations. I've built up my scripts that answer this (one is a monte-carlo style method and the derives differentials for the moments and then infers their maximum entropy distributions). Unfortunately, I can't find a published model (or any model for that matter) to test my scripts on... It has to be linear because non-linear uncertainty propagation is still an open problem and a bit too challenging for a bachelor thesis. Does anybody know of a compartmental linear model that describes a cellular funct…

please help me how to dissolve chitosan suggest any method or protocol.

Dear everyone I need to produce a protein complex from a bacterium. The protein complex contains four proteins and all of these proteins are encoded in an operon. Can I clone the whole operon into a usual expression vector and express and purify the complex? I expression vector, for example, pET, has its promoter, but can this promoter control the expression of all the four protein? In my opinion, the vector promoter can control the expression of the first (the ORF nearest to 5'-terminus) protein, but can it also control the expression of the proteins far away from it? Best regards.

Hello. Can someone help me with this plasmid, want to know if gene expression will be turned ON or OFF in the presence of Cre. plasmid.sbd

Hello, I have been thinking about this specific question for a while now.. from what I remember the process is simple and usually goes one way - cartilage turns into bone. ..but is it possible to turn a grown bone into .. cartilage? I am a mechanical engineer, so that part of biology/chemistry is really not my thing. I was recommended this forum. King regards

Hello, I have a question which may be trivial but I cannot seem to wrap my head around it: I ordered a certain antibody from an US american vendor, which was delivered to me in form of a powder and I dilluted it to 1mg/1ml for my experiments. I used 50µl to achieve that concentration, just as suggested by the vendor. I used samples with 0.2µl, 2µl and 4µl of my AB solution for my experiments, and it worked perfectly fine. MY antibody ran out and I wanted to ordered some more, problem was, the vendor changed their product and they are only selling the antibody in a concentration of 0.1mg/1ml anymore. I know the formula c1V1 = c2V2. Would that mean I have to use ten t…

Hi everyone, I'm an undergraduated student and I have been extracting DNA from seeds successfully for a couple of weeks. But when I try to visualize the quality of the DNA extracted using agarose gel with BrEt, my gel gets orange. The DNA was extracted according Doyle & Doyle protocol. I'm adding 3ul of BrEt for each 50ml of agarose (I'm adding BrEt in the gel). This souldn't happen. Can anyone help me? I'd like to solve this problem before my professor request me to show my results As a loading buffer I'm using a solution with bromophenol blue and sucrose

Hello everyone, I need to cap gRNA's. I've found a product online to do so. However it requires that the gRNA has a di- or triphosphate at its 5' end. I'm new to the CRISPR and RNA world in general. Do gRNA's have this di-/triphosphate at their 5' ends? I know this seems like a relatively easy question to find out, but I've been rummaging through literature for hours trying to find this one tiny bit of information and have come up with nothing.

Are there lives on earth that don't eat others? Is it possible to live without sacrificing / killing others for food? Can something like this be created with science? And I don't mean lab meat or plants. I know it is all about finding enery to live, but the way lifeforms are getting that energy is so cruel.

Hey guys, was doing an IB IA experiment on how pH affects efficiency of breakdown of lactose by lactase. In my experiment, I found that at pH 4, when I would vortex the solution of lactose mixed with lactase the solution would become very cloudy and I would see little “fibers” as it seems on the photo below. When I did glucose tests I found that there was no glucose in those solutions, which would seem to indicate that the lactose was not broken down. However, a reaction evidently occurred since the solution went from clear to cloudy, so was wondering if maybe due to the acidic environnement the lactose was broken down into glucose but that the glucose formed a polysaccha…

This is the most interesting topic to me in molecular biology so far. I'm looking for a direction to go in for after graduating with a molecular biology degree from UW madison. How cells are and how they function is amazing to me. I want to do something that goes in depth to describe these aspects.