Questions tagged [cell-culture]
Cell culture is the process of growing and maintaining living cells in vitro.
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How to take precise/low number of cells from cell lysate? [closed]
I would like to know that how can we take low or precise number of cells from a cell lysate? (without using any protein quantification assay).
Let say,
If I have a cell line having cell density 5x10^...
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1answer
64 views
Continuous (yeast) culture system satisfying multiple criteria
There are multiple ways yeast cells can be grown in liquid cultures.
Batch cultures are easy to prepare but cell density, medium composition and physiology change over time
Chemostats allow to ...
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1answer
18 views
Are cryovials really better than regular tubes for cryopreservation?
What is the rationale for using cryovials instead of regular, sterile centrifuge tubes for the storage of mammalian cells?
With a good aseptic technique and without touching the cap directly, there ...
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1answer
34 views
What does it mean to use DMSO as a dissolvant in biology experiemnts?
In many biology publications, I saw that dimethyl sulfoxide (DMSO) is used to dissolve drugs. However, the cell-based assays are still performed in water-based medium such as RPMI or PBS.
My ...
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0answers
533 views
What is the difference between enrichment media and selective media?
Enrichment media
These media are used to suppress commensal bacteria while allowing the pathogen to remain viable and grow.
[Source: Ananthnarayan and Paniker's textbook of Microbiology.]
...
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0answers
22 views
What are the normal IC50 values for doxorubicin at 48h and 72h?
Different IC50 values are reported in papers for the U937, K562 cell lines and PBMC and all of them are given on ng ml. I do not understand well, why these values change too much, even if the ...
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0answers
12 views
Can you gain valid toxicological data about a detergent in cell cultures?
I just looked at a paper that in one assay tested a variety of chemicals and chemical mixtures against human cell cultures. They exposed HEK 293 cell cultures for 24 hours to the various chemicals.
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0answers
36 views
Isolation of Intact Granules from Mast Cells
How to isolate intact granules from mast cells without using sucrose and percoll?
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1answer
125 views
What is the recommended culture volume for HeLa cells and seeding number for 384 well plate wells?
For 24 well plate wells, thermofischer recommends to seed 0.05E6 cells with 0.5 to 1 ml of medium. What are recommended numbers for a 384 well plate well?
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1answer
29 views
Growth mediums required for human cell cultures
So i would like to try a culture some of my keratinocytes just to see if i can do it. Ive read about a few different types of growth medium such as DMEM and RPMI but i am not sure about when to use ...
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1answer
38 views
Major effects on cells grown with 5% FBS supplemented media instead of 10% FBS?
I maintain a few cell lines in the laboratory (industrial R&D) that I use regularly for experiments. I realized today that the media i prepared for the week on monday was only supplemented with 50 ...
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0answers
23 views
What is(are) the mechanism(s) that stop cells from fusing in vivo?
I just learned about the phenomenon of 'cell fusion' in which two diploid somatic cells can combine into some aneuploid cell in vitro and proceed to proliferate in culture. Apparently this can even ...
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Polysporin/antibioltic ointment and agar plates
Has anyone tried applying a layer of antibiotic ointment to the surface of their agar after autoclave sterilization?
A friend suggested that I use an antibiotic in my agar. So it got me wondering if ...
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0answers
15 views
Micro-propagation of Moss in Agar (sterilization?)
I'm having trouble sterilizing my moss sample for micro-propagation. Moss is basically a sponge and it has a massive surface area. I tried Isopropyl alcohol figuring it had a very high probability of ...
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0answers
32 views
Low cost cell free expression system
I am a graduate student looking to incorporate some protein engineering into my training. I have been reading a lot about E coli lysate based systems, but they still require 3rd party additives like ...
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1answer
42 views
Chunks of cells after trypsinization
Recently I've came across a problem after trypsinization of my stably transfected CHO-cells. When I add medium to rinse off the cells from the bottom of the flask, there are usually big chunks of ...
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0answers
13 views
Need to learn about basics of eukaryotic cell culture and transfection
Can someone please suggest books/ online courses/ other resources to learn about cell culture and transfection theory as well as techniques? I've been reading research papers and everyone uses methods ...
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1answer
59 views
Minimum hardware and knowledge to study effects on live cells [closed]
I'm very interested to study the effects (or reactions) of different forces (magnetic fields, electric fields, etc) on living tissues/cells.
I know I have to have a living cell, the force applied and ...
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1answer
36 views
What are the meaning the nomenclature in high cell density cultivation for the production of a protein? [closed]
I'd like to know the meaning of these terms in a HCDC studies of a modified strain.
Max specific yield (mg/g DCW)
Max volumetric product yield (g/l)
Specific product formation rate Qp (mg/g DCW/h)
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1answer
74 views
Microinjection intestinal organoids
I am attempting to microinject small intestinal organoids, using the Eppendorf FemtoJet 4i microinjector and Femtotip capillaries, and have come across several issues. This is a new set up in our lab, ...
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1answer
30 views
Is there a standard way of measuring culture nutrient levels in real time?
I am working on optimizing growth rates for a culture, and one thing I'm trying to monitor is nutrient consumption rates to pinpoint any bottlenecks, i.e. the culture goes through all the calcium in a ...
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2answers
25 views
Do PC-12 cells have to be stored in nitrogen?
My lab has been storing their PC 12 cells in the -80 freezer... upon arriving here and investigating a new project I see that it specifically stated to be stored in nitrogen vapor? Is this the ...
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0answers
22 views
Trace nitrogen content in agar
I am wondering if microbiological agar can contain trace nitrogen? I use one from the Sigma Aldrich for preparation of nitrogen free medium.
According to website of the manufacturer there are some ...
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1answer
92 views
Is it possible to make anaerobic media too reducing?
I've been struggling to grow an anaerobe (P. gingivalis), I take every precaution to keep the culture conditions free of oxygen, I was wondering if the conditions can be so reducing that they inhibit ...
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1answer
54 views
Tumour cell injection into a mice [closed]
I am going to inject mice tumour cells into mice to create them tumours and I am wondering if I need to have special precautions for that, even they are cells from mice tumour I am afraid what can ...
3
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2answers
143 views
What culture medium should we use for tap/drinking water bacteria?
We are a group of high school students from Manila who is performing an investigatory project on a topic that we chose which, at first glance, seemed simple, but turned out a bit complicated. We're ...
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1answer
296 views
Do dead cells always contain no nucleus?
If I examine a dead cell, can I be sure that it has not a nucleus?
And what about the other organelles?
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1answer
131 views
Mold identification
I poured some agar plates and tried inoculating them with mushroom spores (I don't think they germinated bc of low humidity), but noticed what looks like mold with crystals on the surface of the agar.
...
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2answers
233 views
293T safety, transfections with plasmid DNA
I am a little concerned with 293T cell lines, I have been working with this cell line for a few years with less frequency. However there were times that i extracted the proteins from these cell lines ...
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1answer
44 views
Yeast contamination with fungus patch
I am working on yeast mutant and I am observing their sporulation efficiency on agar plates. One of my plates got some dark green small fungus patches. I can't grow yeast again and dump this one with ...
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1answer
131 views
Inoculating agar plates with microbes suspended in sterilised water?
We were having a problem with our experiment (culturing microbes on homemade nutri agar) so we decided to change our set-up. It already cost us quite some money. So, we saw this procedure. Can anyone ...
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2answers
83 views
Why E.Coli get bigger if they replicate faster?
When E. Coli divide faster, they tend to have larger volumes. If the same cells are grown in a poorer medium, they'll have longer replication cycles and shrink. What is the explanation of this ...
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0answers
42 views
Are there any techniques for manufacturing exosomes in the lab?
I'm interested in the idea of using exosomes as an alternative transfection agent / delivery mechanism for gene editing applications (CRISPR/cas9, etc).
Information on the matter is sparse.. Does ...
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0answers
219 views
How long can one go with necrosis?
In general, when a limb dies, how long does it take before it falls off? Can you go years with a black and useless limb, or does it just.. fall off right away?
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0answers
42 views
Can anyone expolain this? Cell culture vials have strange hair-like condensation patterns
What is the hair-like polymer that condenses on the caps of the plastic cell vial? Inside vial are cells in a mixture of FBS and DMSO. The vials were frozen slowly in a special isopropanol-filled ...
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0answers
32 views
How long can you store tissue on 4°C before B-cell extraction and culture?
We receive tissue regularly and extract B-cells for culturing, studying differentiation and survival with diffenet stimulation conditions. However, often the tissue arrives late afternoon and might be ...
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0answers
2k views
Why is a DMSO-only Control Important? [closed]
Why is it necessary to have a DMSO alone control when DMSO has been used as the solvent (vehicle) in the treated conditions?
And, in this case, why is the viability of the untreated condition lower ...
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1answer
171 views
Flow Cytometry to learn about Cell cycle
I am posting my Flow Cytometry data here again because I realize that there are many people who are willing to help me, and I can learn a lot from you guys.
In this cell culture Lab, we use Cell U-...
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1answer
465 views
Flow cytometry data Analysis [closed]
everyone.
Since I am new in the flow cytometry technique, I am not really sure how to analyze the result.
We use cell U-937 Lymphoblast.All Cells
Could Anyone help to explain me this one?
Thanks ...
3
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1answer
58 views
How is an RT-PCR representative of the RNA contents in a cell?
For example, we first collect all the RNA contents from a mammalian cell line. Say, for instance, we collect 80 uL of RNA with a concentration of 150 ng/uL. Next, to make cDNA, we take 1,000 ng of the ...
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1answer
391 views
Trypsin and Cell Surface Receptors
Can adding Trypsin to mammalian cells affect the expression of or hydrolyze cell surface receptors?
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0answers
106 views
Pelleting bacterial cells using centrifugation and getting proteins in the supernatant
Do significant amount of proteins from cells find their way in supernatant during pelleting? If the answer is yes then I see two ways in which protein can be in the supernatant
.
1) Through lysis ...
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1answer
51 views
Estimation of cell count of E.coli culture
Can I get some help with an estimation of a cell count in a culture of E.coli cells if we assume we begin with $10^6$ cells, that they divide every 30 minutes and they are incubated for 12 hours?
I ...
2
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1answer
486 views
Mass production of bacteria
Is there a way to mass produce a certain species of bacteria?
Answers I am looking for should not involve a Petri dish: I am only interested in protocols involving, perhaps, more efficient mediums to ...
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0answers
18 views
In Vitro Meat Initial Production
I've gotten interested in the science behind in vitro meat, and I was wondering what would be necessary to create it. Would you initially need a primary culture, or an immortalized cell line? And how ...
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0answers
189 views
Why are my assay absorbance values very low?
I am culturing SH-SY5Y cells in 96-well plates at a seeding density of $1.2 \times 10^5$ cells/mL. I differentiate the cells with retinoic acid for 6 days before giving them treatments. The cells look ...
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1answer
42 views
Why would you plate cells at different densities in a colormetric assay?
The aim of my experiment is to see if a kinase inhibitor reduces cancer cell viability. I am using 2 different cell densities 50,000 cells/well and 100,000 cells/well and different doses of the kinase ...
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3answers
114 views
How to prevent HL-60 cell contamination?
I have thawed Hl-60 cells from liquid nitrogen chamber two times in RPMI 1640 media (containing 10% FBS, L glutamin, penicillin/streptomycin). In the first day the cells remain okay. But when ...
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0answers
280 views
Will dead cells in culture media have any significant impact on Live cells during incubation?
I am generating stable cell lines and have something like 25+ culture flasks to take care of. Ideally I can let dead cells sit in the media with the live adherent without rushing to change media ...
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0answers
54 views
Where am I going wrong in a Reactive Oxygen Species Assay done in N9 cells?
I have followed the modified protocol that was given to me by my senior (who was using for his RAW 264.7 cells - Reference article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3308605/ ) for ...
