Sartorius Midi Plus

Sun, 26 Jan 2025 00:00:00 +0000

When bigger competitors swallow innovative small companies or brands, the product quality can sometimes suffer due to attempts to increase productivity. I do not know whether this is the case for the BioHit Midi Plus pipetting controller, but we have had our fair share of trouble after the rebranding of the BioHit Midi Plus under the “Sartorius” name. It feels like a bad contact issueOur lab has probably about 20 of these. Among them are the (ancient) bright blue type, the dark blue, and the black models. We had and still have many problems with the black, i.e., the newest model . Although charged, these models sometimes suddenly stop functioning altogether. After pushing the aspirate and eject buttons several times, they start working again (as if there was some contact problem). But sometimes, we need to plug the charger cable for a short time into such a temporary dysfunctional pipette to render them again operational. Even though I have used the older (blue) models almost daily for two decades, this behavior is new to me. It is especially disturbing when working in the cell culture: you have just removed the medium from cells and want to add PBS for washing. Now, your cells are starting to dry out while you are frantically searching for a replacement pipetting aid. As the PI, I work less and less in the cell culture, but when I do, this happens to me nowadays every single time with the Sartorius Midi Plus. Product development should make products better, not worseI have also wondered why these pipettes have not developed much over the years. Why is there no up-to-date intelligent charging controller like every mobile phone has these days? I guess there must be some kind of controller, but apparently, it is not up to the task. Some things did change. For example, the oldest models used NiCd 2/3 AA cells, which were later replaced by NiMH 2/3 AA cells. I assume that the charging controller was also updated since these two battery types need different treatments during charging to optimize the battery life span.I feel that the oldest pipettes of this series have been the most reliable and that the lifetime of the newer models has been decreasing over the years. Since I live very close to the lab, I offered to split cells for everybody in my lab over the last Christmas holidays. However, due to the Midi Plus issues, I got very frustrated when I did the splitting. I needed to exit the cell culture to get another pipetting aid, which is always a big hassle. The MidiPlus that I found (also black) worked, but its LEDs started blinking, and there was some beeping, which I had not experienced before with any of the older models. Sloppy user manualLater, I tried to look up from the user manual what the LED messages and the beeping meant. Sadly, I could not find any information in the manual. Why would anybody include such features and then not document them in the user manual? I contacted Sartorius with this very question on December 31. I received an email reply on January 10th, in which the local service representative offered to visit our lab to sort out our problems. However, none of my questions were answered concerning the missing documentation on the blinking/beeping, and only a repeated request resulted in an answer: Red blinking = battery almost outGreen blinking = chargingSolid green = fully chargedBeeping = battery almost outContinuous beeping sound = battery voltage too low, maybe the batteries need to be replaced In the current version of the manual (01/2022), only the green LED messages are mentioned. It is strange that the user manual was distributed with incomplete information for something like 10 years. Did Sartorius not care? Maybe an intern wrote the manual who never used the BioHit Midi Plus for long enough to ever witness the blinking/beeping? However, Sartorius promised that they would add the missing information to the next edition of the user manual. **Should we switch to Integra? Any user experiences with other brands?**When I started my lab, the first Sartorius-branded black Midi Plus we bought was broken right from the start. It never was able to recharge its batteries and went straight for repair. Interestingly, all three of our (original) Integra Pipetteboys are still going strong. Yes, we needed to exchange the batteries, but the Integras have the advantage of running on rechargeable 9V cells, which you can buy almost everywhere where batteries are sold. This is in stark contrast to the Midi Plus’ 2/3 AA batteries, which you need to order from Sartorius for a premium price. I guess that Sartorius sells these batteries for about 10 times the price that they buy them for from the Chinese manufacturer. Unfortunately, Integra does not sell the original Pipetteboy anymore, and I have no experience with the Pipetteboy acu 2. **What is your favorite pipetting aid?**Are you using electronic pipetting aids in your work? I would like to know your experiences: Which brands are reliable, durable, and affordable? I have no problems with paying a premium price for a premium product, but it feels to me that, at this moment, Sartorius’ BioHit Midi Plus only earns the premium designation for the price, not for the performance.

Manually recharging batteries

Wed, 04 Apr 2007 00:00:00 +0000

I have a old-fashioned battery charger from Varta (type 57 037 091 101) that doesn’t switch off the current when the batteries are fully charged. Unfortunately this is the only charger I have e.g for D size batteries (also called mono batteries). The charger lists the necessary charging times for different types of batteries on its back side. If you assume 100% efficiency, the necessary charging time is given by the following formula: charging time (h) = battery capacity (in mAh) / charging current (in mA) The times given in Varta’s table exceed these theoretical times by 24-65%. Mostly they are around 40% longer than the calculated. This agrees with the data given in the usage instructions of my Hama charger that claim that charging time (h) = battery capacity (in mAh) x 1.4 / charging current (in mA) However, I have read on several web sites (e.g. gaiam ) that the factor for charging losses is 1.25 and not 1.4; consequently I still don’t know exactly how long to charge when I need to charge manually. Especially I am wondering whether there are differences in the charging inefficiency between e.g. NiCd and NiMH batteries.

Batteries on Michael’s Domain

Sartorius Midi Plus

Manually recharging batteries