Guest post: Electron Microscopes and your lancets. Because science.

I love the fact that by having a blog, I have access to the thoughts and opinions of all of YOU out there. That’s the whole point of a blog, right? It’s a chance to start a discussion, to hear other’s perspectives and…gain access to their electron microsopes?

Yep, you read that right! I am SO excited to have a guest post today by a reader from Germany named Florian Lang (who you can catch blogging about diabetes and cycling and other things across the pond at his blog right here). Florian, lucky for us, works in an engineering lab and has access to this totally insanely detailed microscope. And even luckier is the fact that like most of us who read this blog, he wanted to know everything about his lancets and needles so he took that microscope power to the next level. Please enjoy his guest blog and incredible images today!

How bad is it to not change the lancet, really? Well, see for yourelf!

by Florian Lang

The honour of a guest post. I’m quite willing to use that opportunity to blab on and on about cycling and the weather and how everything was better in the olden days. No? Stick to one topic? Oh if I have to. Please imagine a sulking three year old here – it’s about the right mental image.

Tiny introduction – basically so you know what you are dealing with. I’m a 30-something old man from Germany, who’s had diabetes for 35 years. Over here things are occasionally different. Very much so, as I find out from time to time. For instance we do not get CGM (continuous glucose measurement) devices paid for by our insurance companies, as they are considered “new technology without proven benefits”. We also actively have to document, that a pump would provide an improvement in our diabetes control (with documentation including all blood glucose tests, sports, carbohydrates, injection site changes for six months – I suppose the German reputation for documenting things thoroughly is not entirely unfounded). On the other hand, we do, of course, have health insurance for everyone. And our employers pay half (roughly) of the insurance premium.

I’ve had phases in diabetes – ranging from well controlled (by my parents) when I was very little, to horribly messy in my teenage phase. I’ve been startled about two years ago by a picture taken at the company barbeque that showed a seriously fat man. My diabetes doctor at the time (himself a bit on the wide side) said: You cannot change this. You’d have to completely change your lifestyle and become a vegetarian. I felt let down (and changed doctor) – and decided to just be a bit more sensible.

“Bit more sensible” turned out to involve more sports (which I occasionally blog about), less food (which I _don’t_ blog about – who’d want to read that?!) and better control of my diabetes. Which meant not only going on lots of training courses during my work hours, but also to finally get a pump and read up on resources. Turns out there are a few available on the internet (who’d have thunk it?).

I’ve also been annoyed (frequently) by doctors’ orders. What especially bothered me (for today’s topic, anyway) was the clear rule to use lancets and needles only once. Always throw them out right after you used them. Waste the 0.5 units of insulin required to fill the needle just in case you dropped it into the dirt on the side of the road. But I’m slightly getting ahead of myself there.

Anyway, the topic at hand today is misuse of pen needles and lancets. I’ll go so far as to extend this to syringe needles as well. No information on pump related stuff, of course, as will become obvious in a second.

When Alexis posted about life hacks, she mentioned changing the lancet maybe twice a month (and this is a direct quote, I’ll have you know!). I know people who tell diabetics off for that. In fact, I was specifically told not to reuse things in every single training course I got. The images shown are usually similar to this one:







Taken from a German pharmacies web-site and available in similar shape and format from many, many English and US sources as well.

The usual symptoms mentioned are pain during the injection or the blood-letting. Some of the sources are curiously dubious, mentioning diabetic dogs, laboratory tests on pig skin and synthetic dummies. Now I don’t mean to appear like a contrary old person (I suppose I actually do), but I never trusted those images and numbers.

Admittedly – mainly because I didn’t feel pain and I certainly did not change my syringes, pen needles and lancets anywhere near as often as recommended (Reality check time: When I go out for a meal and a visit to the cinema I need two injections: for the meal and the popcorn. I’m not going to open my pen in the dark of the cinema, unscrew a pointy, sharp metal needle and leave it in the popcorn container).

So, I checked. Conveniently I work with a scanning electron microscopy daily and thus just need to distract my boss with a cup of coffee, while I quickly put several things inside the vacuum chamber that have previously been stuck into me. I mean… into a randomized male patient, age 30-40 with soft sensual skin. Two of those are true!


Image 2







Now this image (above) is a new pen needle (Novofine 8mm, in case it makes any difference). Unfortunately, the very tip is buried inside the carbon pad that I used to hold this sample. Sorry. However, we can probably safely assume that this tip is pointy and not bent in funny shapes. Because we believe in medical companies having sensible quality control and have had an optimism-inducing beer before writing this post (second German prejudice confirmed, I suppose).

I’ve used that same type (not the same – I didn’t have that much time) of needle several times. I’ll just tell you now, that after 1 and 2 injections it looked exactly the same. Needle shape wise, that is. Some “stuff” ends up stuck to it (we shall call it skin and blood and hope it’s nothing else).









This is the needle after 20 times use (above). Still doesn’t look too bad, does it? Although, I’ll admit, the amount of gunk is not exactly getting better.










Now I admit that that was at the same magnification. And thus fitting my description better than that of the manufacturers. Which was sort of the point. So here is the same image (above), magnified ten times more. Now there is some bending at the tip. Which seems to turn the needle into a grappling-hook-of-skin-ripping (that’s the technical term – look it up!). But the total deformation is still only 5 µm. Considering the total needle diameter of 250 µm that is a deformation of 2%. I think. If my math is right.

The pen needles are by design relatively flimsy, though. They have to be thin-walled, and thin to produce the least amount of PAIN!! Which is in all our interest, so I’m definitely not complaining. Lancets, on the other hand, don’t need to be hollow and can be designed with a bit more stability in mind.









And so they are (above). Solid chunks of steel. With a slight edge to them (two, technically, but we’re not debating their legality in a bar-fight here).

When you ram that thing into your skin – skin breaks (Evidence: look at any diabetics fingertips, although I suppose Wikipedia would stick a [citation needed] here). The big chunk of metal? Not so much …








This is the same needle after 300 blood tests (above). On a male subject, age 30-40 … with unusually soft skin, I am sure.

And because the pen needle didn’t show much deformation in the small magnification here is the enlarged view:








Still nothing. In fact, it would appear that solid steel is harder than skin. Which isn’t all that surprising. Even the Mohs Hardness scale tells us the same.

Summary? It’s not going to cause much more damage if you don’t exchange your needles. I’m tempted to add “ever” here, but evidence is still missing (a well-deserved [citation needed] in this case). There are “things” sticking to the needles, though. Probably just cells and blood and gore and such, but the images above allow a case to be made for “ICK!”.

So I still occasionally exchange my needles. And switched to a pump instead of a pen.

Did you enjoy this post? Why not leave a comment below and continue the conversation, or subscribe to my feed and get articles like this delivered automatically to your feed reader.


Fascinating! It’s nice to see that old. classic photo put to shame. (Great writing, too!)

I get the point ;)

Wow! Very cool! Thanks for posting all of your pics! Even if you had proven the opposite, I’m not sure I would change my lancet device more often. But now I feel better about being a little grubby. I’m quite confident noone would want to publish your data showing that it is not entirely necessary to change needles/lancets every time, but it is practical info for patients LIVING with diabetes. Thanks for sharing!

Thank you Florian. I appreciate the effort to satisfy intellectual curiosity and appreciate even more the open sharing of your findings.

I can tell you that after 50 uses, a BD Ultra-Fine syringe does hurt more than when it is new. Whether this is caused by a deformation of the metal (which you’ve shown is unlikely) or an increased friction due to build up of gunk along the surface of the needle I cannot confirm

Of course, I’m guessing that my skin is not nearly so soft as yours…errr…I mean of the 30-40 year old male test subject. ;)

Not that I’m following all the comments religiously and showing them off to my (poor, innocent) wife along the lines of “look, look, I got another comment!”.

@JPE: There is another factor (which I completely ignored) – the needles were all made of a chrome-nickel-alloy steel (which makes sense, because I wouldn’t want my needles to rust) and are coated with something silicony (that, again, is the technical term). I have no idea what the coating does, but it could be a friction reducing layer to make stabbing yourself less painful. Which could also explain why the needles hurt more after a while.

Well that, and the gunk. Next time I look at something like this, they will definitely be cleaned before analysis. There is a good amount of yuck there.

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