Skip to main content

Electrocompetent Cells of DH5 alpha

Electro competent cells are prepared for DNA transformation. Usually the cell wall of bacteria are very thick and hence, a foreign plasmid DNA can't penetrate into it, very easily. So, we prepare electrocompetent cells, which have reduced cell wall thickness or pores over the cell wall.

So, due to this pores, DNA can easily enter the cell and thus transformation is made easy. In our lab, we did prepare, electrocompetent cells of E.coli DH5 alpha. The procedure for preparing electrocompetent cells is available in various sites. So, am not going to discuss the procedure. If you wanna know it, kindly mail me, I will send you.

Okay, following the procedure, you can prepare electrocompetent cells, but, how to ensure that you had prepared a non contaminated one? Generally, Plating is done.

Just streaking, a LB plate and an Ampicillin LB plate with the cells. You must observe, growth in LB plate and no growth with the Ampicillin plate. If so, then pat your back, you did it.

What's the basic behind this plating? Why an Ampicillin plate?

Generally, E.coli DH5 alpha is not resistant against ampicillin. It will show resistance only after you transform it with a plasmid. (Plasmid gives resistance)

So, If you have contamination with other microbial cells, you will find growth in LB Ampicillin plate too.

:) Got it? Any queries? Mistakes? Comment then! :)

Happy learning! :)


  1. Resistence depends on the plasmid u are using...for pET-33b Kanamycin antibiotic is used...During the addition of antibiotic if the agar is very hot then antibiotic will fail to work


Post a Comment

Popular posts from this blog

Genotyping, Phenotyping, Karyotyping!

We are going to discuss here about three different typing! They are genotyping, phenotyping and karyotyping. Before learning about them let us learn what is genotype, phenotype and karyotype!

Genotype refers to the genetic make up of an organism. Generally the genes of an organism. The genotype of an organism can be represented as BB or Bb or bb based on the gene. If a person is having two recessive CFTR genes, then he will be getting cytic fibrosis. Genotype of an organism has also effect over the phenotype. Thus, genotype is representing the alleles of a gene in general. Genotyping is generally done based on PCR or hybridization.

Phenotype refers to the visible characters like structure, color and also the biochemical characters. This is based on the phenotype. Phenotyping can be done using biochemical assays.

Karyotype refers to the number of structure of chromosomes in an organism. karyotyping is done by staining and visualising the cells under microscope.

Isolation of monocytes from PBMC (Peripheral Blood Mononuclear Cells) - Principle and protocol

Whenever I'm made to realise that I'm not clear enough or good at something, I try to make myself clear with it. It happened today, during my laboratory examination, I was asked to perform monocyte isolation from a given blood sample, but, unfortunately, I was not very clear with the principle behind it.(but, still I managed to complete the experiment as I know the protocol, but, knowing the principle behind each step of the protocol clearly is very important, isn't it?). But, nothing is wrong in it, I made myself clear with it now. That's good, right?

So, let me share with you some basic principle and protocol for isolating monocyte from blood sample.

For isolating monocytes, initially we must isolate PBMC (Peripheral bood mono nuclear cells) from the blood sample. Here, let us make few terminologies clear before starting with the principle.

Peripheral blood sample - It is the blood sample obtained from acral areas of body (in general, it is the blood collected from ha…

One year into PhD - my BTS experience!

Dear readers,
I apologize that I stopped writing since last year. I don't have any great excuse other than poor planning. I was lost on my way to understand marine biology. As you might be knowing, I switched field, moved from my focus over bacteria and human disease related studies to climate change and marine biology. However, my research focus continues to be in molecular biology. Long story short, I was learning all about climate change, ocean acidification, ocean, marine animals in the past year. I even learnt how to spawn and culture oysters. How cool is it? Not cool?! Well, I think it is cool! 
I can setup mini Ocean acidification systems which mimics the future acidified ocean conditions; I even gained some plumbing related skills. This was totally a new experience and I thoroughly enjoyed it. However, I had a tough summer in a rural fishing village in China, learning how to grow oysters from the Chinese oyster farmers (for those who do not know what I am doing: I am doin…