Cycle 7: may the 29 to june 5

Hi guys:

Check this videos related to microorganisms and diseases, take notes in your notebook, for points.



Use this image, as a sample for you to design your own poster about one disease. Instructions in class.

Bring 1/8 of card boar and your lab materials.

See you on class

Cycle 6: may 15th to 21st

Hi guys:

This cycle we will work on the lab using the directions I already gave you.

Check this videos  to learn how to cultivate bacterias

The Streak Plating

This method is conducted with the objective of obtaining one isolated bacterial colony in mind. Isolating a colony is crucial in the identifying the strain of bacteria that grows on your plate. By using this method, you will get surface aerobic bacterial colonies (measured as CFU or Colony Forming Units).

The equipment/materials needed are as follows:

• Nutrient Agar, melted then hardened in a petri dish
• Inoculating loop
• Lamp or Bunsen burner
• A sterile and clean environment

Compared to the other methods (pour plate and spread plate), streak plating do not need a definite amount of bacteria to start with. Usually, when streaking plates, the amount needed is only a loop-full of bacteria from one isolated colony.

So you are probably wondering how we got here. Before you begin, make sure that the area where you will conduct your experiment is clean (using 70% ethanol), the Bunsen burner is turned on (important for air conduction), and the other materials are in place. I shall enumerate the crucial steps below.

Source: mizzoumagic.missouri.edu

STEP 1.

Mark and divide the bottom of the petri dish into four quadrants. Marking it is not compulsory. Just imagine your plate being divided into these four quadrants and that would suffice.

Source: cccmkc.edu.hk

STEP 2.

Flame the inoculating loop until it turns red. This will ensure that most of the bacteria on it would be killed and this would help minimize the risk of contamination. Let the loop cool down for a few seconds. Another way to cool it down is to touch the agar medium (near the edge of the petri dish) for one second before taking the selected bacterial colony.

Source: jilindquist.net

STEP 3.

Take one isolated colony and streak it over the first quadrant of the new plate using closed parallel streaks.

A point to take note of is that when you open the petri dish lid, do not fully open it. By leaving just enough opening for you to streak, it would reduce the risk of contamination.

STEP 4.

After streaking the first quadrant, flame the loop until it turns red. Rotate the plate 90 degrees and start streaking the second quadrant.

Repeat the flaming-rotating-streaking step two more times for the other quadrants.

Here is an illustration that shows the steps of streak plate method.

Source: psu.edu

Here is a compilation of important credible websites that will definitely help you understand more about the topic. These are fantastic sites from various universities and colleges and it is advisable to scan through some of them.

Use this link, to check all the videos and extra information!!!

http://inaniloquence.hubpages.com/hub/How-to-do-Streak-Plating

Don't forget, bring all the materials and the protective elements.

See you on class!!

Cycle 5: may the 8th to 14th

Hi Guys:

This cycle we will start to study general characteristics of microorganisms 

Watch these videos and design a comparative Venn Diagram (in an exam paper), comparing all the groups, for points.

In the second class we will have a quiz related to this topic.





Bring materials for the green wall related to Planet Day celebration, and change the Ecologycal schedule . Im going to give you time to start de new design of the Green Wall. Remember this is a grade.

See you on class!!