Biochemistry and Molecular Biology

The history of protoplast isolation says that the first isolation of protoplasts was done by von Klercker in 1892, by first plasmolysing and then slicing up plant tissues. But what were the specifications of the plasmolysis, e.g. salinity level and time in the solution?

Hi fellow wage slaves, for a HTS experiment i would need a permanent open "ssDNA bubble" similar to a transcription bubble (>13 nucleotides). I am not sure if that's even possible, but the following criteria are important: 1. Open ssDNA bubble within replicable (in E. coli) genetic element. 2. No proteins, nucleic acids, or other toxic chemicals supporting the bubble. Can help during nucleation, but bubble has to be accessible for protein interaction. 3. Stable in bioorthogonal conditions. Physiological pH, salt, 37 °C, etc. I am truly at a loss here, but maybe one of you has the sparking idea. I will put your name on t…

I'm currently doing an undergrad project where we're trying to create 3 CAA (casaminoacid) media's (one iron limited, one plain CAA, and one iron supplemented). We created an iron supplemented media by adding 10ml of 2.6g/10ml of FeCl3 (dissolved in ddH2O) to a bottle of 200ml of CAA media (made up of 4g of CAA, 0.944g of K2HPO4•H2O, and 0.2g of MgSO4). This worked and the media appeared clear. Every subsequent time we've attempted to make this, as soon as the FeCl3 stock solution is added a precipitate forms and we can't figure out why, we've tried adjusting for a more acidic pH but it still happens and it also occurs in other medias like TSB. This also occurs befo…

Vegetables are considered to contain almost no fat. But all cell membranes consist of fatty acids, simplified. Why do they not contribute to the energy content? What is it, that we cannot digest them?

Hey there! We've created in our lab a stable cell line knock-out for a gene (with CRISPR Cas9). By the way, down-regulation (by RNAi) of this gene was able to up-regulate RB phosphorylation on S807/811 (inhibitory phosphorylations). Unfortunately, once the stable cell line was formed, this phosphorylation was not detectable anymore comparing WT e KO. When KO was reconstituted (KO + overexpression of the gene), pRB S807/811 dropped. Does anyone know how this could be explained? I could not find anything in the literature do you know some papers I could read about?

Dear all, for a biological experiment I have acquired 10 mg of CHIR 99021 (laduviglusib). In order to obtain a 10 mM stock solution I had to dissolve the powder in 2.15 mL of Dimethyl sulfoxide (DMSO). Unfortunately, I tried to dissolve the powder in distilled water. That powder is said to be insoluble in water. In order to obtain again the powder I tried to centrifuge the solution (1500 rpm, 20 minutes), hoping that the powder would precipitate, but nothing happened. I would like to know how to dissolve that solution: I sm thinking to put another 2.15 mL of DMSO in the water solution in order to have a stock solution of 5 mM (which would be fine for me). What w…

By what methods is it possible to kill the microbes in foods rich in chitinase without destroying the chitinase? I am thinking of killing the kinds of microbes that can grow on regular agar plates at room temperature.

The assays that I have in mind are disk diffusion assays and assays to determine minimum inhibitory concentration or related. Sometimes these assays are conducted in rich medium (Luria broth, Terrific Broth, or similar). It seems to me that this choice biases against finding inhibitors that target enzymes whose absence is conditionally lethal. If one inhibits an enzyme that produces a metabolite that can be obtained from the medium, then growth of the cells might be impaired little or not at all. If one is interested in developing an antimicrobial compound, perhaps using a medium that mimics human serum is a better choice, but I imagine that there are complications I…

Attached is a copy of a paper I have published with two professors of biology, giving a quantum-mechanical description of some very interesting and novel biological phenomena. I would be very interested to discuss these results here. John Brindley CELLR4 Paper.pdf

Hey does anyone have any ideas on working out the impact of a bra on the volume of sagging breasts? Obviously when they are not in a bra, sagging breasts volume will be smaller than if they are in a bra (and how much they are sagging)...but does anyone know of any formulas or science to anticipate volume change? Thanks!

Hi, I'm trying to reduce my protein but it seems like its not working. I'm wondering if its a problem with the buffer? I am checking for free cysteines using a dtnb assay, I see reduction after adding >1mM TCEP but it is a very small amount, probably <5% reduction. I am dialyzing too after about 1 hr of TCEP addition... so TCEP is not messing with the dtnb assay... Could there be an interaction between TCEP and tris-hcl pH 7.4 buffer? I've tried another buffer too hepes-nacl ph 7.4 but I dont think that has worked well either. If anyone knows if there is an interaction between tris and TCEP tho that would be helpful... Thanks

The title of the thread contributing to mould and human illness's ?

Hi All, I'm looking for a PDB for 7α-hydroxylase CYP7A1 in complex with cholesterol. I've searched in the PDB database and I've found the files for the enzyme alone, and complexed with cholest-4-en-3-one and 7-ketocholesterol, but not complexed with cholesterol. This seems odd to me as cholesterol is its natural substrate. Is it possible that the PDB file doesn't exist, or am I missing something? Thanks! John

I'd like to create a total mg/dL blood cholesterol table that equates to a percentage of total cholesterol in the blood. 100mg/dL total blood cholesterol in % ? 1dL = 100mL 100mg/1000=0.1mL 0.1mL is 0.1% of 100mL ? 0.1% is 100mg/dL of total blood cholesterol ? Then to saturate the blood at 100% total cholesterol; total blood cholesterol would need to be x in mg/dL. 100/0.1=1000 100mg/dL x 1000 = 100000mg/dL to 100% saturate the blood with total cholesterol ? Is this correct or is "mL = mg / 1000" incorrect when applied to total cholesterol?

How to create a mechanism for changing an animal's eyes in response to hunger and satiety? I thought of mTOR1 detection and further expression of the GFP genes that we'll theoretically integrate into model animals eyes. How do I detect activation or inhibition of mTORC1? With the help of which receptors? It is clear that it changes its state depending on amino acid hunger/saturation, but how to send a command to the gene for GFP expression in response to this? How will the genes know when to stop? How can the already formed protein be destroyed after it stops being synthesized? is there anything you can put under the TFEB promoter, at least the same GFP protein with some …

Are Cas proteins synthesized only when an environmental cue occurs, or are they floating around continuously all over the bacterium and actively involved in the CRISPR system only when needed?

Hello everyone I want to know if the exosomes can be stored for a while after isolation or if it is better to store the purified plasma or serum? and If I store plasma/serum samples, Is there a risk of degradation of exosomal biological material? Thank you in advance

Hey guys, In the video above, at around 24:40, one of the doctors states: "If you eat an egg, roughly 50% of that will end up in your bloodstream..." Is this true? If not, should it be made illegal to misinform the public through YouTube? What are the latest scientific evidence suggesting regarding eggs raising blood cholesterol? Also, have done a quick google search and it says that eggs don't raise cholesterol but I suppose cholesterol could be taken up into the bloodstream without our cells taking it up ?? Thanks,

Is Magnesium glycinate dihydrate (magnesium diglycinate) the same thing as Magnesium glycinate (magnesium glycinate)? If so, why are there so many different names to describe the same compound? Thanks,

Hello all, I found a cool infographic produced by Cell Signaling. It showcases the human kinome, though I was not sure about some of its features. I was lost on what exactly the white branches indicate, why are these kinases unclassed? Also, I noticed some kinases were left out. Why is Raf kinase not included but Erk is? If there's a helpful resource that helps me understand the development of the human kinome that would be really helpful. Thanks in advance! the following image was reproduced by Cell Signaling Resources: Protein Kinases | Cell Signaling Technology

Hey guys, I just listened to dr rhonda patrick about magnesium threonate... I have heard that most people are deficient in magnesium and it is generally recommended to supplement with magnesium for this reason. Was just wondering, what the best supplement to take for magnesium? Does anyone have any opinions? Also, does anyone know what the bioavailability of magnesium threonate is? And is it true that it crosses the blood brain barrier? If so, which scientific papers have proven this observation? Thanks, Also, does anybody know whether magnesium sulfate is absorbed at all through the skin (e.g. if taking epsom salt baths)? what are the …

Can anyone think of a natural polymer that is ethanol soluble and water insoluble (hydrophobic)? If a natural polymer with these properties does not exist, what other options are there (excl. ethyl cellulose)?

Hi everyone Mycoplasma detection has been a major challenge for me lately. I do cell culture and use qPCR to detect mycoplasma. In addition to controls(+,-) and NTC, I use 3 different strains of mycoplasma as standards (M. orale, M. pneumoniae and M. fermentans). Some Cts relating to standards are extremely high (sometimes 45!) for a few weeks. This is while I count the samples with a flow cytometer before DNA-Extraction and at least 13x10*6 cells are counted in it. The samples and wells in which Ct indicates greater than predicted (I consider ≤35 to be an acceptable Ct and I had before) appear to be entirely random. I have tested different modes, and …

Symmetry Culture and Science 34(1):061-086 By proposing a numbering of the twenty proteinogenic amino acids deduced from the physicochemical properties of the four coding DNA nucleobases, it is established that this amino acid number, equal to 5x entities, is not arbitrary. Indeed, we demonstrate that many attributes of these twenty amino acids, as a whole, are also 5x in number and that by isolating, since their numbering, the 3x peripheral amino acids from the 2x internal ones, these attributes are divided into ratios of 3/2 as exact value. This is verified both as the physicochemical properties of the 20 amino acids and as the coding configurations of the nucleoba…