July 24, 2015
Okay, let's make this one simple...
Click HERE to answer a few brief questions about how your lab approaches instrument support.
All info is confidential We will publish results in an upcoming post.
Shortest darn blog all year...
June 15, 2015
Most people are taught to think of electricity via the analogy of running water. The volume of water moved from point A to point B is analogous to voltage while the rate which the water flows is like electrical current. Multiply the two together and you have power(P=IxE).
Static electricity is the opposite of current electricity, in that it does not move. It just builds up between two non-conducting materials (like plastic and rubber) and sits there, waiting to discharge (Google Triboelectric Effect). If you have ever touched something and got a brief shock, you have likely experienced static build up and provided the path to ground that discharged that potential energy charge. If you ever touched something and got a prolonged and painful shock, you have probably been electrocuted and may be reading this from the Great Beyond.
Static build-up occurs in environments that are dry. Water molecules help diminish charge build up. Insofar as laboratories are concerned, static is generally not an issue due to controlled temperatures and humidity...but they are not immune. This can be routinely found to be an issue with ill-behaved liquid handlers. Disposable plastic pipette tips have been known to 'hang up' or not eject from their mandrels when humidity levels drop. I have seen tips appear to dance in mid-air, only held to the mandrel by static charges. This is dramatically visible with lower volume (384) tips as their mass is less to begin with and is exacerbated by the use of rubber o-rings on the dispense head mandrels. Rubber, plastic and lack of humidity are the perfect recipe for static cling.
So what can be done? Well, the simple solution is to add humidity to lab. If the lab's HVAC system is not capable of effecting changes, you could place a humidifier near your liquid handler. Just be careful as it is a fine line between adding moisture to the air and saturating your robot. Get a can of Static Guard from your local grocery store. These sprays add moisture (water and alcohol, with minerals and salts removed) and are very effective (albeit temporarily) when sprayed directly on rubber o-rings. Another longer lasting and more pragmatic solution would be to place an ionizing fan right on the liquid handler deck, near your tips racks. These devices add electrical charges to the air (anions, or negative ions) and the fan blows it across your tips which can change the electron imbalance just enough to offset clinging tip issues.
Don't let your labs environment make you retreat from automated assays....wait for it....here it comes...."CHARGE." That just happened. BAM.
Next Blog - Vision Sensors (they can be used for lots of stuff, including pipette tip issues...)
April 27, 2015
Back in May of 2013, we talked about the use of third party tips on liquid handling robots. Well, we got a lot of emails on that one as it seems a lot of people are looking for alternative tip providers, for a number of reasons...but mostly cost savings.
We heard a lot of stories regarding OEM's who threatened to void instrument warranties or even refuse to service instruments that use third party tips. Is that legal? Probably not but, it certainly is unwise and I would imagine that is not a company policy so much as it is a regional sales rep or service engineer who does not want to lose a lucrative revenue stream.
Having worked on the supplier side (at Caliper Life Sciences, now part of Perkin Elmer), I can tell you that most OEM's want end users to buy their tips...and only their tips. Why is that? Well, the biggest reason is that they have invested heavily in the creation of precision injection molds and the logistics required to stock and ship tips. This is not inconsequential and often explains why OEM tips tend to cost more than third party tips. Even when the mold costs have been amortized, stocking and distributing tips is a costly endeavor, as is ongoing quality monitoring.
So, you might be asking, how could a third party tip cause an instrument to fail? The only conceivable scenarios I can think of are:
a) head crashes due to physical differences or
b) 0-rings on mandrels that might wear or deform due to physical differences (polymers or dimensions).
Other than that, it's really a red-herring argument. Our sister division, AssayGuru has performed performance analysis on a number of third party tips for various manufacturers and compared both pipetting accuracy and mechanical reliability. These tests were conducted on various brands of liquid handling robots using both third party and OEM tips. In most cases, there have been no issues and the third party manufacturers we have worked with were eager to find and correct any flaws, prior to launching their tip products.
In my next post, I will detail one such manufacturer who has impressed us so much that we have actually created a new partnership...stay tuned.