University Practical exams

MY VIVA #1
Hi,
During the last practical exams I shared my experience. I shared certain questions with answers which the examiner asked me during the practicals.even i share what i learn  Even this time, I'm going to share a few questions and answers with you. Here we go,

This time I had  exam (Practicals), number  - microbial genetics and yesterday enzymology in biochemistry and - Molecular biology.
Let us start with the Biochemistry and molecular Biotechnology lab.

1.microbial genetics

What I know about streaking :

Purpose of streaking : 
Why to Streak?

1) To get isolated colonies. ( mostly bacteria )
2) To check the presence of microbes in a sample ( sometimes)

Types:

1) Quadrant streaking: The plate is divided into 4 quadrants and streaking is done.
2) Continuous streaking: Continuous streak made from top to bottom.
After this 2nd experment is of procedure of transformation
I.e. simple
Bacterial Transformation:
1. Pipette 200ul sample cells into each of 3 ice cold Eppendorf tubes. Label the tubes Control, 1 ng, and 10 ng (1 ng is 10 -3 ug, or 10 -9 milligrams). The unknown plasmid is at a concentration of 1 ng/ul. Add 1 ng of your unknown plasmid to one tube and 10 ng to the other. Place the tubes on ice for 30 min.
2. Put the tubes at 42oC for exactly 90 seconds. Return the cells to ice for 1-2 minutes.
3. Pipette the transformation mixtures onto labeled plates containing ampicillin and spread them around using a sterilized, bent glass rod spreader.
4. Place upside down in the 37oC incubator in room 305 overnight.
5. 16 - 20 hours later, count the number of colonies on the plate with well-isolated colonies. Put parafilm around the edge of a plate and put it in a refrigerator for later use. Check the control plate to see that no colonies grew on it.

And the viva voce, that was very simple :) I scored 10/10 :)

Okay, let us see some of the questions that examiner asked me.

1) Question: Which gene responsible for antibiotic resistance
Answer: some plsmid have Ability to make host cell resistance to one or more antibiotic and these also transfer the resistance to cell lack R factor i.e. resistance
Sub questi

2)   Question:  What is plasmid and give some examples
Answer: Plasmid is extracellular DNA in prokaryotic oraganism and some are artificially synthesis plasmid also its genetic material ,
There are several types of plasmid

   F plasmid - fertility plasmid
   R plasmid - resistance plasmid
   col plasmid
   Promiscuous plasmid
   Virulence plasmid

3) Tell me role of STET buffer ??

 sir actually it contains Sucrose which helps in maintaining osmotic pressure; Triton X which helps in cleaving the cell wall; EDTA which acts as a chelating agent; Tris HCl is used as buffer.

nice tell me ur roll no ?
sir it's 69 😊😊

  

Bye meet with new subject .....