Bunsen Burner Confusion

[HollyinNNV]

Why do some labs require a bunsen burner and some don't ? How can I tell if I can use a simple hot plate instead?:001_huh:

 

Thanks a million!

Holly

[Myrtle]

Why do some labs require a bunsen burner and some don't ? How can I tell if I can use a simple hot plate instead?:001_huh:

 

Thanks a million!

Holly

 

Some of the labs in my program require an object to be stuck directly into flame, say a magnesium ribbon.

 

I would also think that putting a glass beaker directly on an electric burner could crack the glass?

 

To some extent our science program isn't just about teaching science itself, but preparing the student for the lab skills needed to use lab equipment that they will be encountering in college. I've got bunsen burner anxiety.

[MaryM]

Some chemical changes that require heat need the intense heat of a bunsen burner. We found this out by "experimentation"! Some reactions just won't take place unless the heat is high enough. But many labs can be done with a gas burner and a "plate" to protect the beaker. Whether or not you should invest in a BB is up to you. I always felt that we could learn from experiments gone bad as well as those that worked perfectly. It required a reasoning through to determine the "why". Generally, if you are trying to combine chemicals to create a "new" one the intensity of heat of a BB will be necessary from my feeble experience. BUT, others with chemistry backgrounds can tell you more!!

 

Mary

[HollyinNNV]

Well, we are actually looking at high school biology labs that require the BB. The problem is that this is a co-op class that meets at a church. I'm sure they wouldn't be so keen on a BB in one of their rooms.

 

Holly

[MaryM]

If it's biology then I sure can't think of any reason you MUST have a bunsen burner! What experiments are asking for this item in bio? You surely could replace any of those labs that absolutely had to have a BB, no? There are tons of labs for biology and as far as I am concerned the essential ones were the required 12 for Bio AP. None of those, to the best of my memory, required the BB.

 

HTH,

Mary

[HollyinNNV]

Our chp 19 lab is controlling bacterial growth. It is part of the procedure for inoculating a sterile nutrient agar plate. I guess we will be skipping it.

Holly

[Brenda in MA]

Holly,

 

I'm assuming that they are asking for the bunsen burner to heat up a wire loop that is used to transfer bacteria from somewhere (where?) to the sterile agar plate. The wire loop is typically used in bio labs for bacterial transfer because it's easy to sterilize between samples by sticking it into a very hot flame.

 

Depending upon where you are getting the sample, you might be able to use sterile cotton swabs to inoculate the plates in place of the wire loop. You'd have to use a new swab for each different sample, though. Home training tools sells the sterile packaged swabs. You might also be able to get them at your local pharmacy.

 

HTH,

Brenda

[HollyinNNV]

Holly,

 

I'm assuming that they are asking for the bunsen burner to heat up a wire loop that is used to transfer bacteria from somewhere (where?) to the sterile agar plate. The wire loop is typically used in bio labs for bacterial transfer because it's easy to sterilize between samples by sticking it into a very hot flame.

 

Depending upon where you are getting the sample, you might be able to use sterile cotton swabs to inoculate the plates in place of the wire loop. You'd have to use a new swab for each different sample, though. Home training tools sells the sterile packaged swabs. You might also be able to get them at your local pharmacy.

 

HTH,

Brenda

 

Here's what it says to do:

 

Pick up test tube of E. coli.

Remove cotton plug.

Pass the mouth of the tube back and forth through burner flame.

Insert sterile cotton swab into the bacterial culture.

Remove cotton swab.

Pass mouth of tube back and forth through burner flame.

Replace cotton plug and return test tube to rack.

Swab petri dish.

Hold top of swab in flame of burner till it catches fire.

Repeat with new sterile cotton swabs.

 

In the next step you are controlling the spread of bacteria with disinfectants and antibiotics.

 

First pass forceps through burner.

Pick up a disk of filter paper. Insert disk into disinfectant.

Pick up filter paper and position it in agar plate positioning it against agar till it sticks.

Sterilize forceps with bunsen burner.

Repeat process with other antibiotics and disinfectants.

 

Thanks for reviewing this Brenda!

Holly

[Brenda in MA]

Holly,

 

This sounds like an interesting lab. So you are inoculating several plates with E coli and then putting filter paper with disinfectants and antibiotics on some of them to see how effective they are against the bacteria.

 

It looks like you would have to purchase the tube containing a special strain culture of E coli that is used in labs because it's not harmful. It also looks like the flame is used to attempt to keep the culture tube and forceps free of contamination, as well as to kill any E coli left on the swab after it's used. I would also think that you might need an incubator in which to store the inoculated plates.

 

Seeing the whole picture, this lab does look complicated to do in a church meeting room.

 

If you google this string:

e coli agar plate picture

 

You'll come up with some neat photos of bacterial cultures growing on agar that you could show the kids. The fourth one from the left has 6 paper disks with halos around them in an agar dish containing an E coli culture.

 

Best wishes as you plan your course,

Brenda