Day 12: Isolating the amazing plasmid

Today performed Plasmid isolation.
Having performed this practical quite a number of times at college, felt familiar with the procedure and handling of the work. Ah! it feels good.
While performing the practical, had a great conversation with Vinita Sharma Di.(JRF).
We usually quantify the amount of DNA by measuring it's UV absorption. But why don't we follow the same for protein estimation? Ever wondered? That's because only 3 amino acids are known to absorb UV light and they are, Tyrosine, Tryptophan and Phenylalanine. Since, all the amino acids comprising the protein do not absorb UV, it doesn't give proper estimation. Therefore, other methods are usually used.
The DNA absorbs UV at 260-280 nm. Maximum at 280nm.
The purity of DNA is determined by the A260/A280 ratio of 1.7-2.0
But the main question comes, why does any bio molecule, let's say, DNA, absorb UV?
DNA is a very complex molecule electronically, the part of the molecule that is thought to absorb most of the UV radiation is the aromatic ring of Purine and pyrimidine bases. As we know, there are different energy states in an atom and when an electron jumps from one energy level to another, there is either release or absorption of energy. So, in the DNA molecule, the difference between two energy states of DNA structure matches with the energy of a UV photon and hence the UV radiation is absorbed. 
Find out more: Link_1  Link_2

Another Day wraps up. Day 12 Good bye.

Day 11: Life on campus

"Get the Ice-box"- hearing the voice of Ankita Mam, me and my friend, Silky ran downstairs with the ice-box. Ice- box meant that PCR was to be performed today.

Collected the box of primers, master mix, MQ water vials and DNA templates from -20°C refrigerator and placed them in the ice. Silky took the job of preparing the reaction mixture. wearing the hand gloves and pipette in her hand, she started the job. I sat opposite to her and held the job of crosschecking if the microlitre quantity of droplets were being deposited perfectly into the PCR tubes. Finishing the job took around 45 mins. PCR cycler started it's Job (2 hours approx).

Abhishek sir popped in asusual with his doubts and queries. He is a mastermind. He was preparing himself for an interview. His entry was followed by a brainstorming session with Ankita mam and Vinita Di and covered areas of marker analysis, mapping, Polymorphism, multi-allelism and what not. It lasted for about an hour and the satisfied Anil sir went back to his cabin with new doubts and theories.

As the PCR was almost coming to an end, along with my partner, prepared 3% agarose gel for electrophoresis. It took another half an hour for solidifying. meanwhile the PCR was completed.

We all hurried to grab a sumptuous lunch and returned back. Loaded the samples in the gel that was by now ready and waited for the samples to run. Another half an hour chit chat sitting around the Bench.

Time for documentation of the gel. The gel was imaged, saved and analyzed. Job done for the day.

I was sitting in the lab updating my daily notebook, Himanshu Sir Came up and asked how I was feeling at the Institute( Since I am a Newbie). He sat and explained various concepts about markers. He asked questions, explained the ones I couldn't answer and gave an assignment to read about "Functional markers". So, there comes a homework!

No wonder how time flies.

Wrapped up work by 6 pm and made way to the food court. Yummy Noodles were waiting for the hungry stomach. And there ends the 11th Day of the Training. Back to fifth floor, room number 507.