Demystifying Pipet Tips

Demystifying Pipet Tips

 

Background

I earned my B.S. in Medical Technology from Indiana University in 1971.  This was just a decade after the micropipette's introduction into the market

The first micropipette was patented in 1957 by Dr Heinrich Schnitger (Marburg, Germany). The founder of the company Eppendorf, Dr. Heinrich Netheler, inherited the rights and started the commercial production of micropipettes in 1961.

The adjustable micropipette is a Wisconsin invention developed through interactions among several people, primarily inventor Warren Gilson and Henry Lardy, a professor of biochemistry at the University of Wisconsin–Madison.

I began my career in lab distribution sales with Scientific Products in the fall of 1971 so I literally “grew up” with pipettors.  Having used some of the most unsanitary and inaccurate glass pipette in my training (yes, we sucked dichloromethane into our mouths routinely) I was fascinated by the idea of a better way to move liquid from one place to another.

I retired from VWR International in 2013 and started LPS.  Five years prior to my retirement, I approached VWR with the idea of having a web based pipet tips selector.  “I have pipettor X, tell me what tips will fit.”  I presented this to the company who literally laughed at the idea and sent me home.

I was convinced that this was a tool that was really needed and so I began, in my spare time, to do the research required to construct what became Pipettipfinder.com.  It took me five years and I collected samples of every pipet tip I could find.  I carefully measured and recorded everything.  I visited many of the manufacturers.  Working with programmers, I prepared a huge database and on roughly the same day I was ready to launch, VWR announced that they had developed a “Pipet tip selection tool.”  It only “found” the brands VWR sold, of course, but after being told my idea was foolish, I was never credited by anyone at VWR with the idea.  

 


 

The Beginnings of a Classification System

 

What makes a tip “proprietary”?

 

Pipettor manufacturers have struggled mightily since the 1970’s to find a way to make a pipet tip that will ONLY fit on the pipettor they make.  If you can prevent anyone else from making a tip that will work on your pipettor, you create a de facto monopoly.  How do you go about this?

 

It’s got to be a “better mousetrap.”

  • - It reduces repetitive stress, is easier to eject, and takes less force to load.  (E.g., Rainin Light Touch)

  • - It loads more easily and doesn’t tend to fall off.  (E.g., Thermo Clip-Tip.)

  • - It accommodates multi-channel specialty pipettors (E.g., Thermo Matrix)

  • - It has a unique tip ejector which requires a special hub to work properly.

 

And, it goes without saying, but all of these “better” ideas are patented to keep competitors out.

 

These are just some of the selling points that convince some people to overlook the major downside of buying a pipettor that uses a proprietary tip:  If there is ever a supply chain problem (e.g., the Covid-19 pandemic) you have no second source of supply.  You either stop pipetting or buy a universal fit pipette to tide you over until the proprietary tip maker starts production again.

 


 

What makes a tip “universal”?

This is my definition and I’m sure there are other definitions:  Here is a condensed list:

 

  • - It fits on a cone shaped pipettor hub.

  • - It fits on many different types of pipettors.

  • - For non-macro pipettors, it comes in three standard sizes, small (micro), medium and large.  Small = 10 or in some cases 20uL or less), Medium - >20 to 499 uL and Large = 500ml to 2ml.

 

What are Macro tips (5 & 10ml) advertised as “universal” fit?

There are four different major “styles” of macro tips (and there may be more!):

 

(J) Finnpipette Style - 147mm (L) by 8mm (Hub diameter)  Thermo Finn & Brand pipettors

(I) Eppendorf Style - 120mm X 12mm  Eppendorf & Socorex pipettors

(K) Gilson Style - 123mm X 12.5mm  Gilson, Rainin (non-LTS) 

(H) Universal Style - 145mm X 13mm  Nichiryo, Scilogex, VWR Private Label

 

There is one proprietary macro tip, the (L) LTS Style which, of course, only fits the Rainin LTS pipettor.

 

As you will notice, each grouping has been given a letter designation which I will describe next.

 


 

Pipet Tip Attributes

 

In order to classify pipet tips, I have developed a coding system to help locate the exact tip you are searching for.  Here is a list of the classifications:

 

Position

Description

Code

Macro Volume Tip Type (Always in position 2)

1

Maximum tip volume

 

5ml Macro Pipettors

2

Special Tip Type

H

Nichiryo, Labnet

LT

Rainin LTS

I

Biohit, Eppendorf, Socorex, ErgoOne (old style)

CT

Thermo Clik-Tip

J

Finnpipette, Fisherbrand, Brandtech, SMI, Rainin Universal

MX

Matrix

K

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

Pos  2 or 3

Special Tip Features

 

10ml Macro Pipettors

FT

Flex Top

P

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

FS

Finnpipette 16 channel

Q

Eppendorf, Socorex

GL

Gel Loading Tips

R

Brandtech, Finnpipette, Fisherbrand

PD

Positive Displacement (Repeater)

 

>10ml Macro Pipettors

WB

Genomic (Wide Bore)

X

>10ml Rainin LTS

SI

Siliconized

Y

>10ml Nichiryo

2 or 3

Packaging Options

Z

>10ml Rainin Universal non-LTS

B

Bulk

   

R

Racked

   

RF

Refill

   

IR

Individually Wrapped

   

3+

Options for positions  3+

   

F

Filter

   

S

Sterile

   

G

Graduated

   

L

Low Binding

   

E

Extended Length

   

In final position

Color Options

   

Blank

Natural / Clear

   

BK

Black / Liquid Level Sensing

   

BL

Blue

   

GR

Green

   

YL

Yellow

   

 

The following is a list of the codes assigned to various robotic tips:

 

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)

AB2

Beckman Multimek w/Type II Head + 3772 Adapter

AB3

Beckman Biomek FX-384/NX-384

AC

Beckman Biomek 1000 & Biomek 2000

AD

Beckman Multimek & Sagian Multipette

AE

Agilent / Velocity11 Vprep & Bravo (V11) 96 format

AF

Agilent / Velocity11 Vprep & Bravo (V11) 384 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

AW1

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

AX

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

BB

Biotek Cetus Propette

BC

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

BM2

Beckman Multimek Type II with CCS-style head

BM3

Biomek Multimek AP-384

EDOS

Eppendorf EDOS 5222

GC

Gilson Cyberlab

MWG

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

 

How do I search for tips on LabProServices.com website?

 

  • Example 1:  A 200 uL yellow universal fit tip, in racks, sterile.  Search for 200-R-S-YL.

  • Example 2:  A 1250uL non-sterile bulk tip.  Search for 1250-B.

  • Example 3:  An LTS style 300uL low retention filter tip in racks, sterile.  Search for 300-LTS-R-F-S-L

  • Example 4:  A 5ml tip in bulk, for a Finnpipette.  Search for 5000-I-B.

 

All of the pipet tips on LPS’ website have these codes embedded in the description making it easy for you to find just the tip you are looking for!  If you do not get a result, make sure you have the search in the correct order and try again.  We may not have that particular tip in our offering.  Many of the robotic tips listed above we do not offer for sale.

 

Just one note, I have not differentiated different rack types.  There are single racks, stack racks, side-by-side racks and more that this system doesn’t classify.  Make sure you look at the rack type you prefer.

 


 

 

Summary

Wouldn’t it be nice if every tip maker adopted this coding method?  That would really take the guesswork out of finding the right tip.  Hopefully by publishing this someone may see the value.

 

I never miss the opportunity to give this advice:  DON’T BUY A PROPRIETARY PIPETTOR.  A follow up on this, if you HAVE bought them and you are struggling to find tips, BUY A UNIVERSAL PIPETTOR TO PLUG THE GAP RATHER THAN PAY A FORTUNE FOR SCARCE BRANDED TIPS!  A new pipettor is far less than the cost of a case of tips.  Can you think of a better time to try something new and different?

 

If you are in search of a pipette to reduce repetitive stress, there are many great options available today that weren’t years ago when the LTS pipette was introduced.  The quality, accuracy, and reproducibility of pipettors today is nearly identical in most popular brands.  Making a poor quality pipettor is the kiss of death - word spreads quickly.

 

Finally, don’t be afraid to try something you haven’t used.  There are lots of great options out there and while a familiar “feel” is comforting, looking over the horizon is always a good idea.  Most manufacturers offer demo models for you to try before you invest.

 



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