Some interesting pictures of microscopic things taken by an electron microscope

[Jamal]

 

[porchrat]

They've got an image in there of a fruit fly in flight over a banana. Somehow I doubt the authenticity of that claim.

I'm actually not familiar with the process of getting a colour image out of SEM.

 

[Picard]

They've got an image in there of a fruit fly in flight over a banana. Somehow I doubt the authenticity of that claim.

I'm actually not familiar with the process of getting a colour image out of SEM.

What and where do you study in order for you to question the authenticity of this pix? Not that I doubt you.

I do however think that these images have been "cleaned up" with some image-enhancing software.

 

[boramk]

What and where do you study in order for you to question the authenticity of this pix? Not that I doubt you.

Because high school biology taught us an electron microscope requires the object to be dead in order for us to view whatever we wish to view.
Also, an electron microscopes resolution is super high +- 5um, I'd suspect we'd be seeing pictures of the fly's eye, not the whole fly , might be wrong..

EDIT: I see it is an SEM microscope, the pics might actually be legit.

 

[porchrat]

What and where do you study in order for you to question the authenticity of this pix? Not that I doubt you.

I studied biochemistry but I took some time after hours to do some electron microscopy work above and beyond the brief practicals we did during our microscopy lectures just because I was particulary interested in it. Most of my work was with transmission electron microscopy on snail sperm which is far more powerful but the images aren't as pretty . With TEM you can actually just make out the 2 separate layers of molecules in a cell membrane eek.

Anyway the reasons that I say the image can't be of a fly in flight are:

1) With SEM (as with all electron microscopy) the sample is placed into a vacuum. Ever seen a fly stay airborne in a vacuum? Obviously this is not possible. The reason a vacuum is used is because electrons are very small and when fired from the electron source wouldn't travel very far if they weren't in a vacuum. (they would quickly be deflected or incorporated by far larger atoms and would never reach the sample).

2) As others have pointed out the sample needs to be dead. (nothing living can survive in a vacuum). Though I have to admit that if it is possible that anything is an exception to this rule it is insecta.

3) In order for the electrons to have an effect on what they're striking the thing they're striking needs to be electrically conductive. We normally use a process called sputter coating that covers the sample with a thin layer of gold. In fact if anything that was the most awesome part of what little SEM I did at uni. You haven't lived until you've seen an insect coated in gold . The gold (there are a few other metals used but gold is more common) is used because it creates a nice thin even coating that matches the contours of the sample beneath pretty accurately. The fly in that image isn't gold.

4) With all SEM I've ever done you just see a black and white image. Makes sense considering that the image is merely a representation of electron densities in the sample. The films recording the electrons merely change colour in response to electron presence. Kind of like how xray film changes colour in response to the presence of xrays. They don't change colour to represent the actual colour of the material beneath the gold. The nature of electrons to my knowledge won't allow that.

I do however think that these images have been "cleaned up" with some image-enhancing software.

I suspect that the colours at the least have been added afterwards yes.

 

[porchrat]

Don't get me wrong. They are still beautiful images. I just think they're somehow cheapened by manipulating them afterwards. Heck I'm the kind of person that would hang electron micrographs on my walls at home. I just want them in their original black and white as they emerge from the machine.

 

[ld13]

http://www.psmicrographs.co.uk/about

Electron micrograph images are produced by the microscope in shades of grey. The microscope images have to be coloured to produce the coloured micrographs that we know today. When scanning electron microscopes first appeared during the early 1960s, the images wowed the world but even so, they were all in black and white and it wasn’t until software was introduced to colour these micrographs that they truly came to life.

Many people do not realize what goes into coloured micrographs. Obtaining a suitable sample to use on a scanning electron microscope (sem) is just the start of the process. Each sample has to be cleaned and treated depending on its nature ie. soft tissue would be treated differently to a rock sample. Delicate samples like soft tissue can take hours and sometimes days to prepare. It is never a cut and dried procedure with many samples going wrong and it is quite common for samples to fail in the process and the whole procedure having to be re-started with new samples. Most samples have to be coated in a conductive material to stop the specimen charging in the sem vacuum chamber where the sample is bombarded with electrons. This coating involves the use of a sputter coater which covers the specimen in a fine coat of gold, platinum, palladium or some other suitable conductive material. If the specimen is of soft tissue like a small insect or a piece of plant material or even a human sample of blood or perhaps chromosomes, the sample has to be dried, either with chemicals or with a critical point dryer, a machine which takes all the moisture out of the plant, insect or blood sample. If the sample is not dried then it will vent within the sputter coater and the vacuum chamber causing numerous problems with the sample and the equipment. Once the specimen is dried sufficiently it can be coated but quite often the drying process has not been effective and the sample will distort or collapse under vacuum. This is very often the case with insects such as dust mites, fly larvae, mosquito pupa and particularly tough skinned insects. Plant material invariably has a distortion problem no matter how careful the specimen is prepared.

With respect to microscopic animals such as small insects like the fruit fly, small spiders, weevils, these creatures have to be set out before drying. Their legs have to be arranged as if they are alive and this can be a delicate and tricky operation especially when fine antenna and many legs are involved. Losing a leg or an antenna is a common occurance so more than one sample will be set out at a time to allow for losses. Taking a dead fly from the kitchen window-cill is not an option. The insect will never look life-like if it’s looking dead before it is prepared.

We take pride in our specimen preparations. Wherever possible living creatures will look alive in our scanning electron micrographs. If you require natural history images of insects or other small creatures then take a look at our stock library and image gallery. If you cannot see what you want, we will do a coloured scanning electron micrograph especially for you. Be it plant detail, technology, insects, if we can get it in the sem vacuum chamber, we can get a micrograph of it.

 

[porchrat]

Ah. Thought so. Thank you ld13 and congratulations on being the only one of us with a lick of common sense

 

[mfumbesi]

Lots of nice pics. I can spend a day in there..

 

[Geriatrix]

Love these, thanks!