Dispensing with the Brand Transferpette
17 September 2025
In bacterial genetics, P1vir transductions are used a lot for moving genetic material between bacterial strains. However, the downstream analysis, namely, the process of screening transductants for antibiotic resistance patterns, can quickly turn into a repetitive strain injury waiting to happen. Our standard protocol involves selecting four individual transductants from successful P1vir transductions, purifying them, and growing fresh overnight cultures. From these cultures, we spot 10 µL aliquots across a number of test plates: plain LB as a control, six standard antibiotics (with occasional additions for more specialized markers), and a UV sensitivity test plate. It's systematic and thorough, but also very repetitive when done manually.
The good: dispensing done right
© RudolphLAB, 2025
To make the process easier we bought two Brand Transferpette® electronic micropipettes, one covering the 2-20 µL range and another for 20-200 µL. These pipettes come loaded with features including pipetting, reverse pipetting, mixing, gel-electrophoresis, and dispensing modes. For our specific application, the dispensing function is the star of the show, and it performs admirably. The electronic motor gives the impression of modern precision (even though, of course, this is completely irrelevant for a streak test).
The other modes, while technically proficient, offer little advantage over traditional manual micropipettes, amd in some cases, they're even slightly slower. But for dispensing bacterial cultures across multiple plates, the Transferpettes excel. Once loaded with enough bacterial culture they genuinely improve laboratory life quality.
The bad: short funnels strike again
However, things are unfortunately not entirely hassle-free. For our needs the Transferpettes have a frustrating design flaw: they have an insufficiently long funnel. I already complained about this here when talking about the manual microvolume pipettes from IKA. Even with tips attached, the pipette reaches only about two-thirds into our standard glass culture tubes. This geometric limitation forces awkward angles and occasional acrobatics to reach cultures at the bottom of tubes. Thus, the awkwardness of manual dispensing is replaced with awkwardness of actually getting the culture into the pipette. With a slightly longer funnel the situation would be so much better.
The ugly: NiMH batteries in this time and age? Really?
However, the biggest grievance with the Transferpettes is Brand's inexplicable decision to use NiMH (Nickel-Metal Hydride) batteries, at least when we bought them in 2023. The batteries used last a long time. However, NiMH batteries suffer from the notorious "memory effect" and are particularly susceptible to overcharging damage.
The problem manifests in the form of well-intentioned students who, preparing for experiments, decide to "top off" the battery charge overnight. Given the Transferpettes' long battery life, the units are typically already well-charged, but the overnight charging sessions maximize memory effect buildup and overcharging damage. The result? Both batteries died completely within two years of purchase, necessitating replacement units.
While replacement batteries aren't prohibitively expensive, the situation represents an entirely avoidable engineering failure. In an era where lithium-ion batteries have become standard in everything from smartphones to electric vehicles, Brand's commitment to NiMH technology feels oddly antiquated.
The verdict: functional despite flaws
Despite these shortcomings, the Transferpettes remain valuable laboratory tools for high-throughput dispensing applications. They successfully automated one of our more repetitive tasks. However, Brand could significantly improve user experience by addressing two fundamental issues: extending the funnel length for better tube accessibility and modernizing the battery technology to eliminate memory effect complications.
For laboratories considering similar investments, the Transferpettes represent solid functionality wrapped in occasionally frustrating design choices. They work well for their intended purpose, but come prepared for some geometric gymnastics and battery babysitting. It feels very "aged" that I now have to educate laboratory members about proper NiMH battery care.