A question about quality when it comes to microscope slides.
A question about quality when it comes to microscope slides.
So,
I had a set of cheap 'made in China' slides and when you open a pack, you need to careful clean them all very well before using. They have some sort of oily substance and a little bit of grit that makes using them out of the box very impractical.
So I decided, why not go out and buy some quality-made-in-USA Fisherbrand slides. I received the pack and to my surprise, it is worse than the cheap pack I originally had! I received the slides from a seller on eBay and the package was 'sealed' so I'm very confused by this. How is it that these are worse than the cheap brand? Could they be counterfeit or someone just exchanged them for cheap slides? It's very suspicious.
Here's what I get in darkfield right out of the box.
Then, after some cleaning. This is the best I can do, no matter what I try!
Compare this to my original made in China slides.
Something doesn't make sense, any one else have this issue before? I contacted Fisherbrand but still no word from them. But I was expecting at least better than what I currently bought for $5. I paid $40 for the Fisherbrand slides.
I had a set of cheap 'made in China' slides and when you open a pack, you need to careful clean them all very well before using. They have some sort of oily substance and a little bit of grit that makes using them out of the box very impractical.
So I decided, why not go out and buy some quality-made-in-USA Fisherbrand slides. I received the pack and to my surprise, it is worse than the cheap pack I originally had! I received the slides from a seller on eBay and the package was 'sealed' so I'm very confused by this. How is it that these are worse than the cheap brand? Could they be counterfeit or someone just exchanged them for cheap slides? It's very suspicious.
Here's what I get in darkfield right out of the box.
Then, after some cleaning. This is the best I can do, no matter what I try!
Compare this to my original made in China slides.
Something doesn't make sense, any one else have this issue before? I contacted Fisherbrand but still no word from them. But I was expecting at least better than what I currently bought for $5. I paid $40 for the Fisherbrand slides.
Re: A question about quality when it comes to microscope slides.
This previous experience may be somewhat relevant
viewtopic.php?f=14&t=12805
Especially if the slides are densely stored in a box, each one tightly touching the two neighbors, the chance of corrosion and cloudiness increases.
I'm not claiming that it is the same issue here, but my conclusion was - buy NEW coverslips from an reputable seller.
I bought the good slides from a seller who regularly caters to institutes, yet agreed to supply me a relatively small quantity.
viewtopic.php?f=14&t=12805
Especially if the slides are densely stored in a box, each one tightly touching the two neighbors, the chance of corrosion and cloudiness increases.
I'm not claiming that it is the same issue here, but my conclusion was - buy NEW coverslips from an reputable seller.
I bought the good slides from a seller who regularly caters to institutes, yet agreed to supply me a relatively small quantity.
Re: A question about quality when it comes to microscope slides.
Quality and even more cleanness is quite an issue with slides. You may get terrible ones from great European names and good ones from China. Next order it may be the exact opposite. If the slides are just dirty I simply clean them in the dishwasher. If there are irregularities in the glas itself I simply throw them into the garbage bin. Over time I learned which vendors are more reliably than others.
Re: A question about quality when it comes to microscope slides.
Some slides meant for lab use have a coating to help the sample adhere. You might check the labeling. Others might be dusted to keep them from sticking together. I'd think your Fisher slides will be OK if you just clean them off before using.
Re: A question about quality when it comes to microscope slides.
Does slide quality really matter, though? I know I have had issues with cover slips that are imperfect (either the wrong thickness, or have imperfections in them that get in the way of what I'm looking at). I have never noticed the effect of bad slides.
I agree that it would be nice if the glass was smoother, but do the imperfections that you show here still show up in a meaningful way when there is a drop of water and a cover slip on it? Or even more relevant: do they show up when you are focused on a specimen that is in water or mounting medium with a cover slip over it?
Not trying to doubt you. I've just never noticed it and I am curious.
I agree that it would be nice if the glass was smoother, but do the imperfections that you show here still show up in a meaningful way when there is a drop of water and a cover slip on it? Or even more relevant: do they show up when you are focused on a specimen that is in water or mounting medium with a cover slip over it?
Not trying to doubt you. I've just never noticed it and I am curious.
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Re: A question about quality when it comes to microscope slides.
I guess maybe here in darkfield as you want to make sure all the light entering the sample plane is oriented a certain way
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination
Re: A question about quality when it comes to microscope slides.
Whether these imperfections are visible depends on the mountant and contrast method. Bright field is the most forgiving.
Slide packs sometimes carry a "best before" date, a few years from production on, so one has to buy from a dealer that actually moves stock and always has fresh stuff.
What I don't understand: Most lab glass is borosilicate glass today, but there are no borosilicate slides available on the world market. There are slides named "Duran" which used to be a trade name for borosilicate lab glass but these slides are no borosilicate glass. But they actually are the best ones I know and last longer than the other brands I tried. They behave as if they were from somewhat different glass but there is variation between packs, but on an elevated performance level. So this would be my suggestion for slides: https://www.dwk.com/microscope-slides-f ... -235501103
I was close to getting a load of real borosilicate glass slides but they were just 0,6mm thick so not much use. I'm hoping that I will get some one day...
Bob
Slide packs sometimes carry a "best before" date, a few years from production on, so one has to buy from a dealer that actually moves stock and always has fresh stuff.
What I don't understand: Most lab glass is borosilicate glass today, but there are no borosilicate slides available on the world market. There are slides named "Duran" which used to be a trade name for borosilicate lab glass but these slides are no borosilicate glass. But they actually are the best ones I know and last longer than the other brands I tried. They behave as if they were from somewhat different glass but there is variation between packs, but on an elevated performance level. So this would be my suggestion for slides: https://www.dwk.com/microscope-slides-f ... -235501103
I was close to getting a load of real borosilicate glass slides but they were just 0,6mm thick so not much use. I'm hoping that I will get some one day...
Bob
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Re: A question about quality when it comes to microscope slides.
The best prepared slides I have found come from Carolina Science. Most of the stuff you get from China has a poor mountant that destroys the image under polarization. Others take little care concerning the condition of the specimens. Carolina slides cost more but are much more pleasant to work with.
Greg
Greg
Re: A question about quality when it comes to microscope slides.
Thanks for all the help and advice! Since I mostly use Darkfield, that's how I noticed the issue right away. I will look into sourcing better (newer) slides from a reputable source moving forward. But it's still quite upsetting that I paid so much for such a bad product (probably expired), so I might have to try to get some sort of refund.
I never knew glass had all these issues at the microscopic level. I just assumed it was pretty stable. Good to know now!
I never knew glass had all these issues at the microscopic level. I just assumed it was pretty stable. Good to know now!
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Re: A question about quality when it comes to microscope slides.
Since DF relies on total internal reflection inside the slide glass itself , it then also requires a quite specific slide thickness in order for best performance. Some condensers have the ideal thickness stamped right on the condenser. It is usually a thicker specification than is commonly sold nowadays, which is +- 1mm. All DF condensers should have the slide requirements published somewhere but in the absence of that I would measure a bunch of slides between 1 and 1.25mm and test them using an onion membrane in water as a subject.
Prepared slides are also not the best DF subjects. Some are better than others.
Most of the North American biological supply houses no longer make their own prepared slides. They contract them out to India or China where they are very basically prepared using a minimum number of stains. Half the samples all look alike due to the lousy staining. Fisher probably used to make their own but are the slides you bought from them actually marked made in U.S.A. ? Carolina Biological , as Greg pointed out may still . Triarch in Wi. used to make great slides.
It is unreasonable to expect cheap slides to be very good. The last price I saw many years ago for Triarch slides was about 4.00/ pce and given the complexity of their preparation, especially sectioned slides Iwould be surprised if good ones can be had for less than 6.00/ea. now.
Prepared slides are also not the best DF subjects. Some are better than others.
Most of the North American biological supply houses no longer make their own prepared slides. They contract them out to India or China where they are very basically prepared using a minimum number of stains. Half the samples all look alike due to the lousy staining. Fisher probably used to make their own but are the slides you bought from them actually marked made in U.S.A. ? Carolina Biological , as Greg pointed out may still . Triarch in Wi. used to make great slides.
It is unreasonable to expect cheap slides to be very good. The last price I saw many years ago for Triarch slides was about 4.00/ pce and given the complexity of their preparation, especially sectioned slides Iwould be surprised if good ones can be had for less than 6.00/ea. now.