Know the basics about DTA and TGA :

DTA : Differential Thermal Analysis:

In this technique, Sample (material of our interest) and a reference material (must be inert) are supplied with heat. When there is a thermal transition (i.e., a physical or a chemical change that causes emission or absoption of heat) in the sample, thermal energy is added to either the sample or the reference to maintain both reference and sample at same temperature. This change of temperature is plotted against the programmed temperature.

This can give details such as - Whether the transition is exothermic or endothermic. We can get details such as Glass transition temperature, crystallization, sublimation from the DTA curve.

TGA - Thermo Gravimetric Analysis:

In TGA, the sample is heated under controlled conditions and the loss of weight by the sample is measured. A TGA curve is plotted with weight in Y- axis and temperature in X-axis. It is generally used to determine the characteristics, strength of materials and their degradation temperature.

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Lowry Assay Principle and procedure

Though there are several protein assays available, the most preferred one in many laboratories is "Lowry assay". It is effective in the concentration range of 0.01 mg/ml to 1 mg/ml. And, as an additional info, the paper published describing the procedure and principle of Lowry Assay is the most cited paper in the scientific history. (Feeling like, "Wow! I want to publish one to compete with Oliver.H. Lowry"??? :P) Why Lowry? Though there are several other protein assays, mostly Lowry assay is used in many laboratories. The reasons for preferring Lowry are: sensitivity of the assay, highly reproducible, cost effective, easy to perform. Biuret assay is generally used for higher protein concentrations like tissue samples but, Lowry for less concentrated samples and hence used in most of the molecular biology laboratories where there will be need for assaying comparatively less concentrated protein samples (in most cases where we attempt to produce enzymes). Oth...

Fire in the lab!!! BE CAREFUL!!!! A Lesson learnt!

That day, we were working in our lab under laminar air flow chamber. we were streaking our plates with E.coli. For sterilizing the loop, we were using 70% ethanol. We also sterilized the L rod which we used for spreading , using the same Ethanol. One by one, we started streaking and spreading. I completed my turn, and sterilized the L rod by dipping in ethanol once and shown in flame, and placed it in a tray.Mam instructed, " Ethanol will catch fire , if you place the hot rod over it" . One of my friend, did spreading after my turn, she too dipped the rod in ethanol, flamed the rod and instead of placing in the tray she misplaced the hot rod in the ethanol plate!!!! " oooo... fire fire..." immediately ethanol caught fire..!!! My friend who misplaced., she started crying... Mam shouted, " hey girls, guys run out of the lab...," as the tube which carries LPG for the flame was very close to fire. Suddenly, our lab technician acte...

Galaataa at Chemical engg lab!!! :D :D Bang!!!

Venturi meter Oooo.. Pipes, Flows, Fluid flow rate... A different class of chemical engineering, which i never expected in Biotechnology. Thought that mechanical guys alone read on & deal on this thermodynamics!!! But, I too dealt with this thermodynamics. The chemical engineering lab which includes exercises like, 1) Venturi meter 2) Orifice Meter 3) Rota meter 4) Packed bed 5) Fluidised bed... The list goes on and ends with number 14! But, I do remember only these topics. Completed with the exercise, " FLUID FLOW THROUGH A STRAIGHT CIRCULAR PIPE " in the last lab on thursday!. Here we go with that lab experience. Noted the reading from manometer and stop clock successfully with my two batch mates! Some data we searched for calculation : 1) Density of Mercury : 13,600 Kg/m^3 2) Viscosity of Water : 0.001 Kg/(m-s) 3) We were in need of the area of the collecting tank .... A terrible attempt by me, for measuring the width & breadth. ...

A Butterfly and Biotechnology

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