Recommendations for Viewing Bacteria

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MicroscopyLearning
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Recommendations for Viewing Bacteria

#1 Post by MicroscopyLearning » Mon Nov 29, 2021 4:28 pm

Hello. What microscope would be recommended for viewing bacteria that is around the 400 dollar range. I have been researching and it appears phase contrast would be the technique most suitable for this. Does anyone have recommendations?

Alexander
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Re: Recommendations for Viewing Bacteria

#2 Post by Alexander » Mon Nov 29, 2021 8:07 pm

The technique most suitable is proper staining. Phase contrast is good to take a quick first view.

Any decent bright field microscope may be used to view stained bacteria. Methylene blue ist a good start. Gram is for the more advanced.

Beside the microscope you may want an incubator, CLED agar plates and many more things.

dtsh
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Re: Recommendations for Viewing Bacteria

#3 Post by dtsh » Mon Nov 29, 2021 8:11 pm

If you're hoping to do phase contrast in the $400 range, a used instrument will likely be your only option.
Different areas have different quality brands from yesteryear as the most ecconomical option, so exact suggestions will depend on your location.
Around here (North America) I occasionally see a phase contrast microscope close to that range, but they don't appear to be common (at that price). Patience often pays as sometimes one can find a nice instrument which is poorly described or otherwise advertised in a manner that it doesn't draw attention, but it's a waiting game. I found a nice AO One-Fifty Phase for under $75, but I haven't found such a deal since. Even then, most bacteria in a light microscope of any type are very small targets. It will pay to be very familiar with the phase offerings of whatever company you consider so that you can be more prepared to spot missing parts and features.

All that said, as already mentioned staining will likely get what you're after.

MicroscopyLearning
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Re: Recommendations for Viewing Bacteria

#4 Post by MicroscopyLearning » Mon Nov 29, 2021 9:52 pm

Alexander wrote:
Mon Nov 29, 2021 8:07 pm
The technique most suitable is proper staining. Phase contrast is good to take a quick first view.

Any decent bright field microscope may be used to view stained bacteria. Methylene blue ist a good start. Gram is for the more advanced.

Beside the microscope you may want an incubator, CLED agar plates and many more things.
Besides for staining, is phase contrast still suitable for viewing their basic structure, such as the flagellum, on unstained specimens? I would like to view the bacteria live and staining often kills the bacteria. Any recommendations on things to look for while trying to buy a phase contrast microscope?

Dubious
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Re: Recommendations for Viewing Bacteria

#5 Post by Dubious » Tue Nov 30, 2021 12:16 am

Oliver has a video on viewing bacteria:

https://www.youtube.com/watch?v=aZzRygip5XY

I fear you may be disappointed at what can be seen of the internal structure of bacteria with light microscopy.

MicroscopyLearning
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Re: Recommendations for Viewing Bacteria

#6 Post by MicroscopyLearning » Tue Nov 30, 2021 3:41 am

Dubious wrote:
Tue Nov 30, 2021 12:16 am
Oliver has a video on viewing bacteria:

https://www.youtube.com/watch?v=aZzRygip5XY

I fear you may be disappointed at what can be seen of the internal structure of bacteria with light microscopy.
Yes. I mainly want to view the outside structures and not the inner structures. I would like to view their general shape.

Alexander
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Re: Recommendations for Viewing Bacteria

#7 Post by Alexander » Tue Nov 30, 2021 8:03 am

MicroscopyLearning wrote:
Mon Nov 29, 2021 9:52 pm

Besides for staining, is phase contrast still suitable for viewing their basic structure, such as the flagellum, on unstained specimens? I would like to view the bacteria live and staining often kills the bacteria. Any recommendations on things to look for while trying to buy a phase contrast microscope?
To see the flagellum of a bacterium you may need a very high end microscope. A single objective may cost 10 times your total budget. In most cases you are just able to see the outer form, even with phase contrast or staining. Bacteria are at the very border of what a light microscope could make visible.

What is the extra benefit to watch bacteria alive?

MicroscopyLearning
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Re: Recommendations for Viewing Bacteria

#8 Post by MicroscopyLearning » Fri Dec 03, 2021 5:57 am

dtsh wrote:
Mon Nov 29, 2021 8:11 pm
If you're hoping to do phase contrast in the $400 range, a used instrument will likely be your only option.
Different areas have different quality brands from yesteryear as the most ecconomical option, so exact suggestions will depend on your location.
Around here (North America) I occasionally see a phase contrast microscope close to that range, but they don't appear to be common (at that price). Patience often pays as sometimes one can find a nice instrument which is poorly described or otherwise advertised in a manner that it doesn't draw attention, but it's a waiting game. I found a nice AO One-Fifty Phase for under $75, but I haven't found such a deal since. Even then, most bacteria in a light microscope of any type are very small targets. It will pay to be very familiar with the phase offerings of whatever company you consider so that you can be more prepared to spot missing parts and features.

All that said, as already mentioned staining will likely get what you're after.
Is AO One-Fifty a series of microscope made by AO and are all of this series Phase contrast specifically? I have been looking and am not sure.

Alexander
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Re: Recommendations for Viewing Bacteria

#9 Post by Alexander » Fri Dec 03, 2021 6:08 am

Yes, the One-Fifty was a series of microscopes made by AO and no, most of them are not equipped for phase contrast. Phase contrast equipment was quite expensive in those days.

Dubious
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Re: Recommendations for Viewing Bacteria

#10 Post by Dubious » Fri Dec 03, 2021 8:21 am

If in good shape as claimed, this binocular Motic BA300 with phase turret condenser and phase objectives might work for you at close to your budget. No personal experience, but while not a big name, Motic has a reasonable reputation among the current Chinese scopes.

https://www.ebay.com/itm/392714315029?h ... SwtyxeYB4U

(If shopping on Ebay, be careful that a microscope advertised as phase really does have a phase condenser and phase objectives--I noticed another one advertised as "phase" that the photos showed clearly did not have those things.)

Alexander
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Re: Recommendations for Viewing Bacteria

#11 Post by Alexander » Fri Dec 03, 2021 10:23 am

This Motic would be a good choice.

MicroscopyLearning
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Re: Recommendations for Viewing Bacteria

#12 Post by MicroscopyLearning » Fri Dec 03, 2021 10:23 pm

Alexander wrote:
Fri Dec 03, 2021 6:08 am
Yes, the One-Fifty was a series of microscopes made by AO and no, most of them are not equipped for phase contrast. Phase contrast equipment was quite expensive in those days.
Do you think a compound microscope could be used just as well for unstained specimens as the phase contrast can or would you recommend the phase contrast?

Dubious
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Re: Recommendations for Viewing Bacteria

#13 Post by Dubious » Sat Dec 04, 2021 4:23 am

All are compound microscopes. As for phase vs brightfield, a microscope configured for phase can generally also be used for brightfield; generally it just requires you to rotate the phase turret to the brightfield setting (phase objectives also work for brightfield). So with a phase equipped scope you get both worlds and would be able to deal with both stained and unstained specimens.

MicroscopyLearning
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Re: Recommendations for Viewing Bacteria

#14 Post by MicroscopyLearning » Mon Dec 06, 2021 4:31 pm

Dubious wrote:
Sat Dec 04, 2021 4:23 am
All are compound microscopes. As for phase vs brightfield, a microscope configured for phase can generally also be used for brightfield; generally it just requires you to rotate the phase turret to the brightfield setting (phase objectives also work for brightfield). So with a phase equipped scope you get both worlds and would be able to deal with both stained and unstained specimens.
Ok. This makes sense. Thank you for the explanation.

MicroscopyLearning
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Re: Recommendations for Viewing Bacteria

#15 Post by MicroscopyLearning » Mon Dec 06, 2021 6:44 pm

Dubious wrote:
Sat Dec 04, 2021 4:23 am
All are compound microscopes. As for phase vs brightfield, a microscope configured for phase can generally also be used for brightfield; generally it just requires you to rotate the phase turret to the brightfield setting (phase objectives also work for brightfield). So with a phase equipped scope you get both worlds and would be able to deal with both stained and unstained specimens.
When viewing bacteria with phase contrast, is oil still necessary or is it just recommended?

dtsh
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Location: Wisconsin

Re: Recommendations for Viewing Bacteria

#16 Post by dtsh » Mon Dec 06, 2021 6:53 pm

MicroscopyLearning wrote:
Mon Dec 06, 2021 6:44 pm
Dubious wrote:
Sat Dec 04, 2021 4:23 am
All are compound microscopes. As for phase vs brightfield, a microscope configured for phase can generally also be used for brightfield; generally it just requires you to rotate the phase turret to the brightfield setting (phase objectives also work for brightfield). So with a phase equipped scope you get both worlds and would be able to deal with both stained and unstained specimens.
When viewing bacteria with phase contrast, is oil still necessary or is it just recommended?
I believe it would depend on the condenser and objective. Some condensers, such as the Cat 1201 0.9NA I have on my Microstar IV phase turrent are not designed for oil use while the 1745 100x Ph objective does take oil; so I think it would depend on the combination you happen to have in use. In my example, I could oil between slide and objective, but not condenser and slide; in addition, I am effecively limited to 0.9NA due to the condenser - assuming my understanding is correct.

Alexander
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Re: Recommendations for Viewing Bacteria

#17 Post by Alexander » Mon Dec 06, 2021 9:26 pm

MicroscopyLearning wrote:
Mon Dec 06, 2021 6:44 pm

When viewing bacteria with phase contrast, is oil still necessary or is it just recommended?
Phase contrast does not make things look bigger. It just adds contrast. Bacteria are very small. Using 40x dry objectives you may just recognize bacteria. If you want more there is no way around oil immersion.


btw: I use oil immersion down to a 10x objective. Immersion has its benefits and advantages over dry objectives.

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