How to properly maintain a microscope so it will last longer (Part 1)

big fancy microscope

The purchase of a new microscope can be a significant capital investment. The assurance that this investment will last for many years is a very important consideration. Much like the importance of a good mechanic and routine service to keep your car running well past 100,000 miles, it is necessary to know how to properly maintain a microscope so it will last for twenty (or more!) years.

Part 1 consists of some of the basic steps of a microscope life cycle and when and how to optimally care for the microscope stand itself. Part 2 will dive deeper into the life of the peripheral components (camera, lighting, computer, and software) that round out the rest of the microscope system.

Yearly/Bi-Yearly Service

Many regulatory agencies require a yearly maintenance service on equipment as part of their standards. Outside of these regulatory considerations, a routine of basic cleaning and tuning is the front line of defense against more problematic issues. As the microscope ages, this becomes critical as part availability becomes an issue (more on that in a bit). Basically, if you are working in an environment that allows dust, media, or some other gunk to accumulate on the outside of the microscope, you can be sure that the inside is also being exposed to these environmental factors. Anyone can learn to polish an objective or wipe down the exterior of the system, but the routine internal maintenance is why a trained professional is needed.

forensic comparison microscope with macro lenses


While many of our customers work in ‘dirty’ environments (production floors, research labs viewing live cells, etc.) there are also plenty of very sterile environments where the system is not exposed to many (or any) environmental hazards. Also, consideration should be made to the level of training or microscopy literacy the average user has. In some labs the microscope is only used by one or two very well-trained users; other microscopes will have several different users per day with a wide variance in their knowledge and training of the instrument. So, the user needs to objectively evaluate the conditions of the room or lab that the equipment exists in and work to find a maintenance plan that works best for the situation. It is recommended to not stretch service out longer than two years, even in the cleanest environments. However, not every system needs to be examined every year. If you wait until the microscope is ‘not working’, then you are waiting too long and are running the risk of paying more in downtime, higher labor costs, and replacement parts.

A Word on Objectives

microscope objective lenses in a row of various sizes

The microscope objective is the lifeblood of any microscope system. When configuring a system, you should always try to put as much investment into optical quality as your budget allows. The routine service cycle is also paramount to making sure these objectives last the life of the microscope. Many microscope users don’t realize that objectives are not made to be repaired in the field. So, if you are utilizing oil immersion lenses, or work with samples in media/solution, or the scope exists in a dirty environment, the #1 reason to service the instrument regularly is to protect these vital components. The most common cause of objective failure is immersion oil or media that has worked its way into the interior barrel of the objective. At this point, the user has a very uncomfortable decision to make. They can pay the service engineer to attempt a fix in the field (with little or no guarantee that the issue can be resolved) or the objective needs to be replaced. The objective can be sent back to the factory for proper repairs, but this can cost somewhere close to 2/3 the price of a brand-new objective. This makes it a less-than-appealing option in many circumstances.

A secondary note on users with ‘correction collar’ objectives: if you are working with a microscope system that needs to accommodate both plastic and glass samples, you likely have objectives with ‘correction collars’. These collars operate a mechanism inside the objective that allows for sharp focus at varying sample thicknesses. These collars, if inappropriately maintained, will become frozen in place. If too much force is applied to this mechanism it can break, and the lenses no longer are moved properly to adjust working distance.

Focus Drives and Stages

microscope xy stage and objective turret

Manual, gear and ball-bearing based focus drives do not require re-lubrication very often. But these are often neglected and can lead to pretty catastrophic failures if not properly maintained. The focus mechanisms should be re-lubricated every 5 years or so. This particular service does require a greater time investment on the part of the engineer (and a higher service cost) but goes a long way towards making sure the scope has a long and productive life. If you are noticing any vibration in the focus knobs, or an increase in tension (knobs are harder to turn) then that increase in friction is wearing out the gear mechanisms. You can have so much friction within the system that the teeth of the gears fracture or wear down. Automated focus drives require less maintenance, but they do still have roller bearing tracks that should be given new grease on a similar 5-year cycle. If you are unsure whether your automated system has lubricated mechanical parts, please contact your service engineer and they can let you know.

Much like a manual focus drive, a manual stage requires infrequent but important re-lubrication. The roller bearing tracks that generate the X/Y movement aren’t typically a cause for concern, but the lubricated parts within the drive shaft of the stage should be overhauled every few years. Much like the focus mechanism, if there is vibration in the knobs as you move the stage, or a change in tension, then it is time for a fresh coat of grease.

Automated stages require more attention, but the good news for the customer is that the care of these stages is quite simple and does not lead to a significant increase in cost. The motors of the stage turn a long screw that pushes/pulls the stage along the tracks, and this lead screw should have fresh grease applied during every preventative maintenance call.

For anyone operating a ‘live cell’ system where the stage is within the incubation chamber, this stage lubrication may need to happen multiple times per year. The humidity within the incubation chamber dries up the grease on the lead screws very quickly and can rapidly lead to failure of the stage if not properly cared for.

Old Scopes and End-Of-Life Considerations

Congratulations, you have taken great care of your microscope and it is still going strong 25 years later. No need to worry about replacement, right?

Well, not exactly…

old Leitz microscope in vintage brass

The reality of the situation is that eventually, the manufacturer is going to cease creating spare parts for an old generation microscope. Furthermore, every spare part that gets manufactured and then sits on an inventory shelf costs the company money over time, driving down the value that exists around keeping a very robust stock of replacement parts for these systems. What this means for the user is that budgeting for the replacement of your microscope should begin in advance of the time when the microscope is beginning to fail. Purely mechanical microscopes do carry an advantage in this race against obsoletion, the less electronics it contains the less things can lead to an end-of-life failure. The grim truth is that eventually the microscope is going to have something go bad on it that cannot be replaced.

If your microscope is of an age where parts were long since ‘phased-out’ and not being produced regularly, you fall to the mercy of the internet at large to secure spare parts. These parts are typically used or refurbished, priced at a premium, and not commonly available. So you are paying close to full price for a part that isn’t coming with a guarantee of long-term viability. Many users find themselves falling into this ‘death by a thousand cuts’ type of microscope failure, where they keep putting a used-parts-Band-Aid on their issues. In many instances the customer will be spending money in labor and parts that can add up to the price of a new stand pretty quickly.

There is some good news in all of this doom and gloom; the pricier parts of the system (cameras, objectives, perhaps even the trinocular head) might transfer from older models to newer models. These particular items’ configuration tends to change less over time than the stand itself.

Final Thoughts

For many customers, a microscope that is broken or failed will directly result in losses in productivity, profit, and customer satisfaction. It is important for the money managers and decision makers within your business to be aware of how much money a proactive approach towards microscope service and upgrading can save in the long haul. “Pay me now, or pay me later”. An investment now in the long-term viability of your system (including budgeting for periodic upgrades) will pay for itself in peace-of-mind that you won’t be staring down a sudden, large quote for a costly repair or replacement situation.

Please stay tuned for part two, where we will elaborate on the other components of the microscope system like cameras, computers, and software, and how a similar proactive approach will keep your work efficient and customers satisfied.

Happy Imaging!
-Anthony

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