Questions tagged [lab-techniques]
Questions relating to protocols, procedures, and good practice when using laboratory equipment.
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What's happening in the "C" and "T" stripes of a covid test kit?
I have a COVID home test kit which produces C and T (control and test) stripes when the solution is applied to the strip. Something similar happens in pregnancy test kits.
I understand the purpose of ...
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How sterile is sterile when working with nucleic acids to prevent contamination?
I am reading up on preparatory work on working with nucleic acids and a lot of the instructions speak on excessive procedures on cleaning environments with high %ethanol and making sure the equipment ...
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Role of calcium chloride during competent cell preparation
I am aware of the fact that $CaCl_2$ settles down on the cell wall making it less negative may be by forming bond with Teichoic acid. Also due to the positive charge it attracts DNA (DNA is negatively ...
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How does SDS-PAGE separate based on mass?
In SDS-PAGE, electric field and mass-to-charge ratio are approximated to be constant for all proteins. Also, if $F=qE =ma$, then $\frac{m}{q}a=E$.
Thus, all proteins must migrate with a constant ...
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Why is thrombin time (TT) normal range longer than prothrombin time (PT)?
Reference range for the TT is longer than that of the PT.
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How long can I store extracted RNA?
If I extract RNA from a (leaf tissue) sample using a one-step phenol:chloroform extraction, how long can those samples be stored at -80°C? And how many times can I defrost and refreeze them before ...
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How long will a typical bacterial strain keep in a -80°C freezer?
I know that a -80°C freezer is the recommended means of long-term cell-line storage, and that cells will typically not last long in a -20°C freezer. But how long will a typical bacterial strain (e.g.,...
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Are there issues with filling PCR tubes to capacity?
I'm planning to scale up a PCR reaction, and I'm wondering if filling the PCR tubes to the maximum volume of 200 ul would be a problem. It would mean a lot less pipetting as I would only need 1/4 of ...
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introduction to Chip Seq
I hope this question is suitable for this site. I am concerned about the Chip experiment part so I think it should be okay. I am a Applied Math student starting to get into bioinformatics and so I've ...
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Alternatives to CFU plating for measuring number of viable cells?
I am hoping to measure growth rates of a bacterial culture in several growth conditions. I am concerned that these growth conditions may cause cell death, which would lead to a decreased ...
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Measuring protein concentration, Bradford vs. Nanodrop?
I know that the bradford assay is a very standard way of measuring protein concentration after e.g. a purification. However, in the lab that I work in now they normally only use nano drop at the 280nm ...
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How sterile is working next to a bunsen burner?
When I was still doing lab work, many people would just wear gloves and work next to a bunsen burner because the clean benches were all in use.
This was mostly for plating bacteria like Bacillus ...
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Short, concise, practical manual for doing experimental biology
I am am physical scientist working in biology, and have recently started doing experiments. I would like a manual akin to "Numerical Recipes", but for the lab: straight forward, easy instructions on ...
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What is an Ihh-/- mouse?
This one is too basic question:
I just came across $Ihh^{-/-}\ $ mouse. Is that means this mouse devoid of that gene Ihh. What is this sign called and are there other such representations?
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How C. Elegans is used for siliencing genes
The experiment that is using C. Elegans to silence the Genes. I have a question about Why and how C. Elegans can use the DNA plasmid that is generated with the gene of interest in the bacteria by ...
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Optogenetics - How do microbial opsins work?
I'm just introduced to the optogenetics method and am having some trouble grasping the genetics (of the optogenteics) part of things.
So we have Retinal and Opsin that form Rhodopsin molecule that ...
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Why do many DNA solutions contain additional compounds?
DNA solubility data in only water is scarce.
A previous question asked for a quantification of DNA solubility in water. It seemed like it would be easily answerable, however isn't quite that simple ...
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What is the advantage of indirect ELISA over direct one?
I guess the answer is about indirect one giving less error due to selectivity but how exactly does that happen?
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PBST vs. TBST buffer in western blotting
What is the advantages and disadvantages of using either PBST or TBST in western blotting, or while working with proteins in general? Are there other buffers which are also used for western blotting, ...
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Can you measure plasma glucose with a regular glucose meter?
I'm wondering if plasma glucose can be measured with a regular glucose meter and strips like this. I know these meters are normally used to measure whole blood glucose, but can they measure plasma ...
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What is the difference between 4th generation sequencing and NGS?
The generation of sequencing technologies has come on leaps and bounds and there are stark differences between the types of technology used. There is a great Q&A here What is the difference ...
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