Prepared media plate sterilization methods

The following presentation is by Scott J. Bradley and…

Copyright 2013

In this video, I’m going to show you why…

You have some choices when it comes to…

Media Plate Sterilization Methods!

You’ll learn: Several methods of media plate

Sterilization…

How:Each sterilization technique works –

and…

Which method is commonly used in the micro lab.

How’s that sound, OK? Great!

Let’s get started…

Why Sterilize Media Plates?

Media plates are used in many different industries and sciences to grow specific types of bacteria.

In order to be sure we are culturing, or growing the type of “bug” we want, (our target organism), we use specific types of food, called agar.

Also, to be sure we do not cross

contaminate our experiment, we

want to make sure that we start

with a sterile media plate.

Sterility means the absence of all living things!

Clker.com

What Methods are used to Sterilize Media Plates?

First off: Gamma Radiation

One of the most widely used means ofsterilizing media plates is by the use ofGamma Radiation.

A high energy photon is emitted from anisotope source, (Cobalt 60), which in turn

creates an electron disruption

in products (ionization).

If it is a living cell, this kind of

disruption will cause DNA and GAMMA RAY BLAST!

other structural damage to the cells.

Photon induced molecular changes instructure result in death, destruction, andgenerally a really bad day for any receivingorganism!

Gamma RadiationThis type of sterilization is usually

reserved for larger processes,

but also for things like fruits!

Wanna build a Gamma Radiation

plant in your back yard for fun?

Here’s what they look like….

PS: You’re gonna need a really big Budget!

Second Up: Ethylene Oxide

Ethylene Oxide – EO, or EtO, is a chemical compound commonly used for sterilizing a wide variety of items, including medical instruments and

single use diagnostic tools.

Sterilization occurs through

time, humidity, temperature,

and gas concentration.

Disruption of organism reproduction is caused by DNA destruction with the Ethylene Oxide acting as an alkylating agent.

Lardbucket.org

OK …. so , why don’t weuse…Ethylene Oxide?Certain items like some pharmaceuticals or

electronic components can’t take

high temperatures, or steam heat.

Let’s see, what else…oh yeah –

ethylene oxide is very poisonous, and…

you need lots of special precautions and

bells and whistles just to use it safely.1

1(Bells and Whistles You Say? OK – more specifically : Pure EtO gas has a boiling point of 10.73 º C. at atmospheric pressure. Most of the time, it is mixed with Nitrogen or CO2. This is an explosive condition that requires the Intrinsic Safe material (ATEX) zoning, for security of staff and personnel as well as for security of the gas mixing process itself.

So… there’s some good reasons not to use it for fun and sterilization!

And Number Three on Our List:

Autoclaving to Sterilize Media plates can be sterilized via steam

autoclaving as long as they are made of glassor autoclaveable plastic.

Autoclaves kill organisms using steam heatunder pressure, over a certain period of timebased on the batch load.

Autoclaves can be dangerous

to operate, and require a skilled

technician as in all of the

previously mentioned

sterilization methods. (photo courtesy of MedicalExo.com)

Fifteen minutes at 15 PSI at 121 degrees C is acommon autoclave run configuration.

Are Your Media PlatesReally Sterile?

How do know that your media plates are sterile?

When you run a batch of

samples, analysts will run

a positive control, and a

sterile control with each

batch, or set of samples.

A positive control, is a plate that is run, or analyzed after having been inoculated with a certified and known bacteria, or target microorganism.

Usually in the US, we use bacteria strains certified from the ATCC, or American Type Culture Colony.

E. Coli on Modified m-TECc. Aquaplates, Prepared Media Plates

Sterile Controls in your

Runs A Sterile Control, is a plate that is

inoculated with sterile water or nothing, and incubated along with the rest of the batch to assure that the plates themselves are not a causal agent in any cross contamination issues that may arise.

No growth on a sterile

media plate.

And Number Four:Groovy-UV: Ultraviolet Sterilization

Although there are even more exoticmethods for sterilizing objects such asmedia plates, the last topically relevantmethod we shall talk about in thispresentation is UV, or ultravioletsterilization.

UV produces some UV-C and short waveemissions which wreak havoc with thenucleic acids in the DNA and RNA oforganisms.

Works great for disinfecting

residential water

systems as well.

(don’t look too closely – the light is harmful to your eyes!) ; - )

Now……you know about some Sterilization Techniques!

I hope this short presentation has been helpful for you.

If you’d like more information of this type,please feel free to visit us at:

http://www.aquaplates.com/report---pass-your-dmrqa.html

Grab Your FREE REPORT: How to PassYour DMRQA in Micro Every Time!

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