A Pipette Tip Classification System

A Pipette Tip Classification System

For more than 15 years, I have been trying to answer one deceptively simple question:

“What tips fit my pipettor?”

When I began the quest to find an answer, I was working for VWR International. We sold dozens of brands and customers were always asking the same general question: “Will a VWR brand tip fit on my Finnpipette?” or something similar.

I decided to make it my mission to find an answer. I collected every type of tip I could find. I amassed a huge collection of different types of pipettors. I collected every compatibility table that was ever published. I attended trade shows and interviewed various manufacturers. I visited various tip manufacturers.

After collecting all of this information, I created a website: www.pipettipfinder.com. The goal here was simply to help people find tips that would work properly on their pipettors. It has been in operation now for 12 years, and gets hundreds of hits daily.

Not all manufacturers want this information made public.

If you sell pipettors, your revenue stream will actually come from the tips. Your goal is for the end user to continue purchasing your brand of tips. Since pipettes were introduced way back in 1962, manufacturers have employed countless methods to ensure labs continue to buy tips from them. Here is just a partial list:

  • Developing and patenting a proprietary tip design. Rainin LTS, Thermo ClipTip, Matrix
  • Convincing scientists through paid studies that other brands lead to experimental errors. Eppendorf
  • Extensive patenting of tip design or composition and promoting the differences or suing their competitors for patent infringement. Not naming names here but do a quick patent search on Google and you will quickly figure it out.

The only companies OK with you learning that tips other than the pipettor brand you have will fit are companies making tips as their primary product. Labcon North America, Sorenson / Axygen (Corning), Scientific Specialties and Molecular Bioproducts (MBP is a Thermo company) are examples. Most of the private label tips offered are made by one of these companies.

Companies such as these have contributed much to the knowledge base of which “Universal” tips actually work and have done testing to prove the claim. I have found their compatibility charts to be the most reliable source of information.

What if there was a universal classification system for every pipet tip?

If so, then there would really be no need for a website like Pipettipfinder.com! You would be able to go on any seller's website, search for the code for the type of tip you want for your pipettor, and all of the matching tips would be displayed! This is very similar to finding chemicals by using a CAS number search..

I credit this original idea to the person who came up with Axygen part numbers. It is based on that model.

Classification System Described

EXAMPLE: 200-R-F-S-G-L-YL = 200uL Tip in racks, Filtered, Sterile, Low-Retention, Graduated, Yellow

Position

Options

First

Maximum tip volume in microliters

2-Special Design

FT-Flex Top, GL-Gel Loading, PD-Pos. Displacement, WB-Genomic, SI - Siliconized.

2+ Proprietary

LT-LTS, CT-ClipTip, MX-Matrix, FS-Finnpipette 16 channel, Robotic (see list below)

2+ Packaging

Packaging (B-Bulk, R- Racked, RF-Refill, IR- Indiv. Wrapped

3+ Modifications

F-Filter, S-Sterile, G-Graduated, L-Low Binding, E-Extended

Last-Color

[Blank]-Natural/Clear, BK-Black/LLS, BL-Blue, GR-Green, YL-Yellow

Code

Robotic Pipet Tip (Always in position 2)

AA

Beckman Biomek, FX-96, Biomek NX-96 & Multimek

AB

Beckman Biomek FX, Biomek NX, Biomek 3000 & Multimek (Span-8)

AC

Beckman Biomek 1000 & Biomek 2000

AD

Beckman Multimek & Sagian Multipette

AE

Agilent / Velocity11 Vprep & Bravo (V11) 96 format

AG

Tecan Genesis Freedom, Freedom EVO. Cavrp & Miniprep with LiHa

AH

Tecan Freedom Evo, TeMo, GenMate & Aquarius

AI

Corbett CAS-1200 with LLT & X-Tractor Gene

AJ

Perkin-Elmer Janus, Evolution P-3, MiniTrak & PlateTrak w/96-Well Head

AJ1

Perkin-Elmer Evolution P-3, MiniTrak & PlateTrak w/384-Well Head

AK

Perkin-Elmer Janus & MultiProbe

AL

Zymark/Caliper RapidPlate, Presto, SciClone, Allegro & Zephyr

AN

Qiagen Biorobot MDx, 3000, 8000, 9600 & 9604, Rosys and Colibri

AO

Biotek Precision & Precision XS

AP

Aurora Biomed Versa

AQ

Dynamic Devices Oasis LM

AS

ProGroup Wellpro-3000

AT

Molecular Devices FLIPR

AU

Tecan Oasis / Genmate

AV

Protodyne

AW

Molecular Devices Liberty with "Type A" or CCS 384-Well Head

AX

Biotek Precision 2000, Genetix, Tecan GenMate, and Tecan Te-MO Workstations with 1- or 8-Channel Head

AY

Molecular Devices Liberty with "Type B" or Liberty 384-Well Head

BB

Biotek Cetus Propette

BC

Tecan Genesis, Mini Prep, Cavro & MultiPROBE II HT/HT EA

BD

Beckman Multimek Type II with CCS-style head

BE

Biomek Multimek AP-384

BF

Beckman Multimek w/Type II Head + 3772 Adapter

BG

Beckman Biomek FX-384/NX-384

ED

Eppendorf EDOS 5222

GC

Gilson Cyberlab

HT

Hamilton STAR, STARlet, STARplus and Nimbus

MW

MWG Operon Gene Sequencer

TA

Tecan and Axon Instruments PatchXpress

TM

Matrix Hydra DT and Matrix PlateMate 2x3 and PlateMate Plus Systems

TV

Thermo Versette

Macro Pipettors (5ml and greater)

Code

Macro Volume Tip Type (Always in position 2)

5ml Macro Pipettors

H

Nichiryo, Labnet

I

Biohit, Eppendorf, Socorex, ErgoOne (old style)

J

Finnpipette, Fisherbrand, Brandtech, SMI, Rainin Universal

K

Gilson, MLA, Ovation, Volac, Rainin non-LTS, Ergo-One

10ml Macro Pipettors

P

Biohit, Gilson, Rainin non-LTS, MLA, Labnet, ErgoOne, United

Q

Eppendorf, Socorex

R

Brandtech, Finnpipette, Fisherbrand

>10ml Macro Pipettors

X

>10ml Rainin LTS

Y

>10ml Nichiryo

Z

>10ml Rainin Universal non-LTS

Large volume (macro) pipettors pose a particular challenge. These pipettors fall generally into one of three or four categories. The critical dimension on these large tips is the inside diameter at the hub. If it is too small, it won’t go on the pipette. Too large and it falls off.

tip dimensions

To illustrate, take the Eppendorf/Biohit 5ml category. Eppendorf’s inner diameter is 11.84mm. Labcon tips measure 11.32mm and Wheaton tips measure 12.63mm. But all are classed as Eppendorf style. The length of the tip can vary as well, but doesn’t dictate whether it will fit or not.

Based on the tip manufacturer’s statements (or implied fit as indicated by X?) the following table indicates which of these tips fit into each of the five categories for 5ml tips:

Finpipette (J)

Gilson (K)

Epp/Biohit (I)

LTS (L)

Universal (H)

Rainin RT-5000

X

Labcon 1028-860

X

Nichiryo BMX-T

X

Gilson F161571

X

Labcon 1025-860

X

Finnpipette 9402010

X

MTC Bio P4305

X?

Vistalab 4058-5000

X?

Epp 0030071662

X

Labcon 1027-860

X

Brand 702600

X

Axygen T5000C

X

Wheaton W851362

X?

Fisher Maxi 02-681-410

X

Globe 151246

X

Globe 151244

X

Globe 151247

X

Labnet P3998

X?

SSI 4440-10

X

Sartorius 780308

X

VWR 89087-350

X?

VWR 82018-842

X

VWR 82018-840

X

SSI 4420-00

X

There is no “universal” fit on macro tips. If the tip vendor states that it fits a specific pipettor, that is the most reliable information you can rely on and how the above chart was constructed. If it is not stated, where an X? is located, my advice is to request a sample and try it before making a large purchase.

The price of macro tips varies widely. Buying tips in bulk rather than small packs of 100 will save you a ton of money.

The Changing Market of the Rainin LTS Tip

On October 30, 2001 a patent application was filed by Kenneth Rainin, James Petrek and Steven Nielson for a “Pipette with improved pipette tips and mounting shaft.” US Patent 20030082078A1 was granted. That patent was reassigned to Rainin Instrument LLC (owned by Mettler Toledo.) The patent’s 20-year life has expired and this design is no longer proprietary.

The LTS tip and the range of pipettors manufactured by Mettler became very popular over the 20-year life of this patent even though the Rainin pipettors were some of the most expensive on the market. Rainin/Mettler fought tooth and nail not only to keep competitors out of their tip business but to exclusively sell directly to end users. They lost one of these legal battles with Labcon, who was the only company offering compatible tips for many years. No other manufacturer was willing to go up against Mettler.

During the Covid-19 pandemic, Rainin quickly ran out of tips. Many people’s only option was to buy universal pipettors and non-proprietary tips. Shortly before the pandemic, Rainin had purchased Biotix, who is also the holder of numerous pipet tip patents. LTS style tips were offered under the Biotix brand through distributors, but also became hopelessly backordered during the pandemic.

The floodgates have now opened and LTS style tips are available from any number of sellers, even pipettors based on the LTS design.

The Mettler name has always represented quality and this company relies heavily on the “Swiss Made” mantra to bolster that image. However the original Rainin pipettors were a knock-off of the Gilson pipettor. “Pipetman” was at one point the “Kleenex” of the pipettor world. Everyone wanted one, and as it so happened, Dr. Kenneth Rainin at the time had an exclusive distributorship for Gilson in the U.S. When he came up with the idea for the LTS design, he built a knock-off of the vaunted Pipetman and sold it as a Rainin. Mettler loved it, it made him a rich man and they ran with it. To this day, Gilson and Rainin pipettors share the same basic design.

Will the LTS Design become the future standard, replacing the universal tip?

I wouldn’t bet against it. Changing the barrel design to accommodate an LTS style tip couldn’t be a big deal. My guess is that in five years, both styles will be available from nearly every manufacturer.

Physics dictates that this type design takes less force to mount and then eject. So many attempts have been made to reduce the forces needed to mount a tip without leaks, including making the tops of the tips softer and more flexible. But these are just workarounds, and all have their downsides.

If it comes down to a ClipTip vs. the LTS design, in my opinion the ClipTip will lose every time. Clips just make sure the tip doesn’t fall off but does nothing to ensure an air gap doesn’t exist.

Not banging the pipettor vs banging is an easy sell.

No longer being proprietary and with competition now in the market, there is no reason the LTS design should not be widely adopted. Any pipettor maker could easily provide a barrel modified to accept LTS style tips. I predict this will be an option offered by many pipettor makers in the near future.

Are Chinese manufactured tips inferior?

tip rack

For many years, tips made in Asia - and especially China - had a reputation of poor quality. While it is still possible to find “bad” tips, the Chinese have put those days behind them. They have the same state-of-the-art injection molding machines that we have and are keenly aware that their products need every certification possible to assuage the fears of U.S. buyers. Quality is key and they know it.

Are U.S. made tips better? Not necessarily. A U.S. manufacturer that we used to purchase from made 1250uL tips that worked perfectly on a major customer’s pipettors and when the next lot number was produced, they wouldn’t stay on the shaft! After an analysis they said that there was no guarantee that lot-to-lot that this wouldn’t happen. That was the end of our relationship and we lost a major customer as a result. We have been selling tips made in China for many years and never experienced a problem like this nor have we ever had a complaint of any sort.

Utilizing the Classification System

Distributors want you to buy high margin items (e.g., their private label products) and they want to steer you away from similar items with lower profit margins or from less favored brands. (Big companies pay big money to make sure the little guys get back row seats.)

If the above classification system were built into the descriptions of each pipet tip, then using it, an end user would be able to bypass all the hide-and-seek games distributors play. Imagine how this would work on Amazon, or better yet, on Google searches!

Finding tips to fit specific robotic system is an even greater challenge. Also, manufacturers literally scare the Dickens out of end users if they start looking at some other brand of tip! Think of how useful it would have been during the pandemic to be able to search for robotic tips using this system.

Limitations of the Classification System

There are so many different types of racks available that trying to describe the difference between a StackRack and an EcoRack was too much. The goal is to find a tip that fits and THEN choose the type of packaging you want from that array of choices.

Pipet manufacturers will resist adding these classifications. While they may want you to buy their tips to fit on a competitor's pipettor, they are more interested in keeping you from buying any competitor’s tips! The same applies to the big distributors, for which this system would upset the ability to steer you to a preferred product or brand.

Summary

We will at some point in the near future retire PipetTipFinder.com, and fully integrate this classification system into our website. Please feel free to adopt our system - it is public domain and requires no royalty or license fees.



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