DR . R. MAHENDIRAN RAMASAMY

An autoclave is a machine that provides a physical method of sterilization by killing bacteria, viruses, and even spores present in the material put inside the vessel using steam under pressure. Autoclave Principle/ Working The autoclave works on the principle of moist heat sterilization, where steam under pressure is used to sterilize the material present inside the chamber. The high pressure increases the boiling point of water and thus helps achieve a higher temperature for sterilization. Water usually boils at 100°C under normal atmospheric pressure (760 mm of Hg); however, the boiling point of water increases if the pressure is increased. Similarly, the high pressure also facilitates the rapid penetration of heat into deeper parts of the material, and the moisture present in the steam causes the coagulation of proteins, causing an irreversible loss of function and activity of microbes. This principle is employed in an autoclave where the water boils at 121°C at the pressure of 15 ...

  REAL TIME PCR   AIM:  Demonstration of Real-Time PCR through experimental samples  INTRODUCTION:  Real-time quantitative PCR allows the sensitive, specific and reproducible quantitation ofnucleic acids. It monitors the amplification of a targeted DNA molecule during the PCR (i.e.in real time), not at its end, as in conventional PCR. Real-time PCR is the technique ofcollecting data throughout the PCR process as it occurs, thus combining amplification and detection into a single step. Using PCR, specific sequences within a DNA or cDNA template can be copied, or “amplified”, many thousand- to a million-fold using sequence specific oligonucleotides, heat stable DNA polymerase, and thermal cycling. The PCR is the cyclic reaction based on the rapid change in temperature during each step. During PCR, our gene of interest is amplified as well as quantified. Real-time quantitative PCR is the reliable detection and measurement of products generated during each cycle of...

  I SOL A T I ON A N D SE P ARA T I ON OF C H R O M OSO MA L D N A FR OM B A C TE R I A   AI M : To iso l a te a nd s e p a r a te t h e c h r omosomal D N A f r o m ba c te r ia   P RI N C I P LE:   G e nom i c ( c h romosomal) D N A f rom e i t h e r b ac t e r ia, plant or a ni m a l ce ll c a n be iso l a ted b y l y sis m e thod. F or pl a nt ce ll or b ac t e ri a l c e l l , f i rst ce ll w a ll is me c h a nic a l l y disrupted. The ce ll w a ll is b r o k e n e n z y ma t ic a l l y using e n z y m e s l i ke l y so z y me. W h e n b a c te r ia a r e l y s e d und e r a lkaline c ondi t ions both D N A a nd p r oteins a re p rec ip i tat e d. A f ter the a ddi t i on of ace tate- c ontaining n e utr a l iz a t i on buf f e r the la r ge a nd le s s supe rc oi l e d c h r omos o mal D N A a nd p rot e ins p rec ip i tat e , but the small b ac te r ial D N A plasmids ca n r ...