biotix inc. the biotix guide to pipetting · pdf fileboth types of micropipettes work...
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BIOTIX INC.
THE BIOTIX GUIDE TO PIPETTING
Biotix Inc.Technological breakthroughs found only in the most advanced liquid handling tools available. http://biotix.com/ [email protected] +1 858 875 7696
understand and get the most out of your pipettes to get better results in your experiments
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01 | THE HISTORY OF PIPETTE DESIGN 0
02 | TYPES OF PIPETTES 2
03 | FINDING THE RIGHT PIPETTE TIP 4
04 | CARING FOR AND MAINTAINING YOUR PIPETTE 8
05 | ERGONOMICS AND PIPETTING IN THE LAB 10
06 | SUSTAINABILITY 12
07 | FURTHER READING 14TA
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CHAPTER 1
THE HISTORY OF PIPETTE DESIGN
2 Descroizilles’s and Gay-Lussac’s pipettes are most
similar to the modern day serological pipette. Today’s
serological pipettes are either made of disposable plastic or
reusable glass. Like Descroizille’s design, these pipettes
have a gradation scale on the side to accurately measure
and transfer between a fraction of a milliliter and 50 mL of
material. In use, serological pipettes are inserted in to a pipette
plunger apparatus. When depressed, the plunger creates a
partial vacuum that allows the liquid to be drawn up in to the
serological pipette. The user can easily control the amount of
liquid drawn in to the pipette.
3 In the 19th century, Louis Pasteur needed a way to
transfer small amounts of liquid without contamination.
He would take a glass tube, heat the center over a burner,
draw the tube out to make it very thin in the center, and
then snap it in half to yield two fine-tipped pipettes. The
fine-tipped end was placed in liquid and a balloon or rubber
bulb was placed on the larger diameter end. When the bulb
was squeezed, it creates a vacuum that draws liquid into
the pipette. Similar pipettes are still used today in this form
or as an all-in-one plastic version, which is referred to as a
transfer pipette. Typically, a transfer pipette does not have
measurement markings and are not meant for transferring
accurate amounts of liquid.
Like most modern day pipettes, they transfer between a fraction of a milliliter and 50 mL of material.
Francois Descroizilles and Joseph-Louis Gay-Lussac created the first pipettes in the 18th century.
In the 19th century, Louis Pasteur needed a way to transfer small amounts of liquid without contamination.
1 Contrary to popular belief, the earliest pipettes
were created not by Louis Pasteur in the 19th
century but in the 18th century by two French chemists,
Francois Descroizilles and Joseph-Louis Gay-Lussac.
Descroizilles in particular is considered the patriarch of
the volumetric analysis field. He created the precursor
to today’s buret and pipettes called the berthollimetre
and alcalimetre, respectively. In an 1824 paper, Gay-
Lussac made some modifications to the alcalimetre and
coined the resulting instrument a “pipette.”
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THE BIOTIX GUIDE TO PIPETTING
THE HISTORY OF PIPETTE DESIGN
5 Heinrich Schnitger, a postdoctoral student at the
University of Marburg, Germany was frustrated with
trying to accurately draw small volumes of materials using
the Carlsberg pipette. To overcome this issue, he created
a piston-pump driven glass pipette starting from a syringe.
His design created a more accurate and durable pipette that
didn’t require mouth pipetting. He was awarded a patent for
his design in 1961. Schnitger’s pipette design was adopted
by the scientific device industry and this basic design is still
used today.
Schnitger’s design created a more accurate and durable pipette that didn’t require mouth pipetting.
For his research, Levy created the first reported pipette for small measurements.
4 The Carlsberg pipettes took Pasteur pipettes one
step further. In the 1930s, Kaj Ulrik Linderstrøm–
Lang in the Carlsberg laboratory in Denmark wanted to
study single cell metabolism. He passed the problem
of scaling down the typical laboratory techniques to a
research fellow named Milton Levy. For his research,
Levy created the first reported pipette for small
measurements. Similar to Pasteur, he made these
pipettes by drawing a glass tube over a lit Bunsen
burner and pulling one end to create a thin, capillary
tube. However, each pipette was then calibrated with
mercury or dye to measure a specified volume of
liquid. Also, the liquid was drawn into the pipette by
mouth pipetting—a technique in which the scientist
uses his/her mouth to suck up the liquid into the pipette.
Carlsberg pipettes had a number of limitations—they
were not consistently manufactured (though some were
mass-produced), broke easily, did not ensure accurate
volumes despite calibration, required extensive
experience, and could cause the user to ingest
whatever was being drawn up in to the pipette.
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THE BIOTIX GUIDE TO PIPETTING
THE HISTORY OF PIPETTE DESIGN
CHAPTER 2
TYPES OF PIPETTES
While micropipettes have been developed in all sizes to address specific laboratory tasks, mechanistically there
are two main types: Air displacement and positive displacement. In overall basic mechanism, both air and positive
displacement pipettes are similar.
Both types of micropipettes work similarly to Schnitger’s basic pipette design. Both pipettes require depression of
a piston-driven plunger. The user sets the volume to be drawn up prior to pressing the plunger. Depressing and
releasing the plunger creates a vacuum that draws the set amount of liquid up into the pipette. However, because of
slight differences in design and how the sample is drawn up, they are used for very different purposes and materials
in the lab.
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THE BIOTIX GUIDE TO PIPETTING
TYPES OF PIPETTES
Air displacement starts with dialining in your volume which moves the internal piston to the correct position
to be able to draw the appropriate volume. Once that volume is set you depress the plunger which moves
the piston down in the pipette. Once you emerge the tip into the liquid is when the vacuum is created and
once you release the button the piston moves up and aspirates the liquid to whatever setting you put on
the pipette. Once you have the sample in the pipette tip and you push the plunger again the piston will
move back towards the position you drew the liquid from. Then the blowout stage which is fully pressing
the top button pushes the piston past its position when you began the draw which creates pressure greater
than the volume drawn making it expel all the remaining liquid.
Figure 1. Comparison of Air Displacement
and Positive Displacement Pipettes.
AIR DISPLACEMENT
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THE BIOTIX GUIDE TO PIPETTING
TYPES OF PIPETTES
The downsides of the air displacement mechanism are that the accuracy of the pipettes is affected by
temperature, atmospheric pressure, and density/viscosity of the sample. In addition, the air cushion
can allow highly volatile samples to evaporate into the air space, which can lead to contamination of the
pipette.
Fixed volume Single channel
Manual
Repeat function (repeaters)
Variable/adjustable volume Multi-channel
Electronic
Calibrated to dispense one volume One pipette tip per pipette
Manually press and depress plunger
A larger volume is taken up into a reservoir. The sample volume is taken up and dispensed with a push of a button
Can change and set volume dispensed by pipette
One pipette holds many tips that simultaneously measure and dispense the same volume of liquid (often used with multi-well plates
Pipette operated by battery force
A key feature of air displacement pipettes is that a cushion of air is left between the pipette shaft and the
sample, so the sample is never allowed to come into contact with the shaft. This, in combination with
the use of disposable pipette tips makes air displacement pipettes very convenient for repeated, routine,
accurate pipetting work. In biological labs for example, air displacement pipettes are the instrument of
choice for measuring most aqueous solutions and buffers, including common biological materials like DNA,
RNA and proteins.
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THE BIOTIX GUIDE TO PIPETTING
TYPES OF PIPETTES
POSITIVE DISPLACEMENT PIPETTES
Positive displacement pipettes act more like
syringes. A disposable barrel/tip is placed
on to the pipette (see Figure 1). The desired
pipetting volume is selected and the piston
moves down into the disposable barrel. The
piston comes into direct contact with the
sample so no air cushion exists between the
sample and the piston. When the plunger is
released, a partial vacuum draws the liquid
up into the barrel. To release the sample,
the plunger is pressed again and the piston
pushes the liquid out of the barrel. The entire
barrel/tip is disposed of between samples.
A positive displacement pipette applies
constant aspiration force to the sample that
is not affected by the physical characteristics
of the sample. Therefore, they are useful
for accurately pipetting viscous or dense
solutions. They are also used to pipette
corrosive or radioactive samples to prevent
contamination of the pipette as well as cross-
contamination between samples. Positive
displacement pipettes are also used when
working with volatile samples that would be
susceptible to evaporation in the air cushion
of air displacement pipettes.
In comparison to air displacement pipettes,
the types of positive displacement pipettes
are limited. They are generally only available
as repeat or manual, single channel variable
pipettes.
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THE BIOTIX GUIDE TO PIPETTING
TYPES OF PIPETTES
Figure 2. Exploded Diagram of an Air
Displacement Pipette.
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THE BIOTIX GUIDE TO PIPETTING
TYPES OF PIPETTES
CHAPTER 3
FINDING THE RIGHT PIPETTE TIP
In the days of mouth-drawn Pasteur pipettes (and even earlier), one size of pipette tip had to fit all applications.
But today’s technology has advanced to the point where there many types of tips are available to suit a myriad of
applications. Picking the right tip for your application is important. In fact, the tip is one of the most important factors
in accurate pipetting – it is at least as important as calibration and pipetting technique.
A well-calibrated pipette isn’t very helpful if the wrong type of tip is used. In addition, using the wrong tip can lead to
contamination, and even force you to exert more force while pipetting, leading to repetitive stress injuries.
The sheer variety of available tips can be confusing, but this guide will help you make the best choice for your needs.
Pipetting must be precise and accurate—that is, you
must be able to consistently deliver the exact amount
of material in precisely the right location. This requires
tips that are manufactured to reduce any variation in
volume and sample delivery. That means you should
avoid cheaper tips that may have manufacturing
imperfections such as flashes, protrusions, scratches,
air bubbles, bends or impurities. Also, make sure
there is little tip-to-tip variation in a batch of tips.
Finally, be aware that some lower quality tips may
contain additives in the plastic that can contaminate
samples and affect experiments.
The design of the tip is also critical. While it may
seem like just a piece of plastic, many features of a
pipette tip can improve performance. One example
is BLADE® technology by Biotix in which the distal
end of the pipette tip has an optimal bore size to wall
thickness. This prevents droplet formation reducing
touch-off and save you time with each aspiration.
QUALITY
GENERAL CONSIDERATIONS WHEN CHOOSING A TIP
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THE BIOTIX GUIDE TO PIPETTING
FINDING THE RIGHT PIPETTE TIP
Tips should fit snugly on to the end of your pipette.
This ensures precision, avoiding any aspiration of
air into the pipette as you draw samples. Tips should
also release easily from the pipette without falling
off prematurely. Poor fitting tips can lead to sample
leakage and may require additional insertion force
contributing to repetitive stress injury. Biotix tips come
with FlexFit® technology and “flex” at the insertion end
to provide a better fit on a variety pipette types.
Pipette tips represent a small cost compared to
time and reagents. Pipette tip costs can vary greatly
depending on the design of the tip and the materials it
is made from. One way to reduce costs is to purchase
high quality tips delivered in a reload format. Reloads
allow you to rack tips in seconds saving you time, and
come in a multitude of formats to fit your budget.
FIT PRICE
Figures 3 & 4. Packaging
of Bulk Tips.
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THE BIOTIX GUIDE TO PIPETTING
FINDING THE RIGHT PIPETTE TIP
UNIVERSAL VERSUS BRAND SPECIFIC
Most pipettes are compatible with universal pipette tips. However many pipette manufacturers recommend using
their brand-specific tips designed for use with their pipettes. In most cases this is unnecessary, but there are a few
pipettes on the market that require a specific pipette tip. When selecting pipettes consider whether or not a specific
tip is required versus universal. The requirement of a specific pipette tip can lead to higher costs and disruptions
in supply. In addition, if brand-specific/pipette-specific tips are used, then each brand of pipette used in the lab will
require purchase of a different tip. Therefore, the most economical choice is to use universal pipettes and tips.
Universal tips are designed to fit most commercially available pipettes containing a standard-diameter barrel. These
tips meet a large number of laboratory requirements, including reagent transfer and high accuracy measurements
and can be used for a wide variety of applications, as long as they are of good quality and fit your pipette snugly.
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THE BIOTIX GUIDE TO PIPETTING
FINDING THE RIGHT PIPETTE TIP
Barrier, also called filter, tips contain material near the proximal end of the tip that prevents your sample from
contaminating your pipette or damaging your equipment. The filter works by protecting the pipette barrel from aerosols
and liquids during aspiration of samples. This prevents contamination of the pipette and subsequent samples. Filter
tips are essential when working with toxic or caustic solvents or radioactivity. They are also used when conducting
experiments that require the highest level of purity, such as with PCR or RNA.
BARRIER (OR FILTER) TIPS
Figure 6. Pipette Tip Without Low-Retention Technology
Tip Types
Figure 5. Tip With no Barrier Compared to Tip With
Barrier.
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THE BIOTIX GUIDE TO PIPETTING
FINDING THE RIGHT PIPETTE TIP
In many standard pipette tips a tiny amount of residual
liquid will to cling to the sides of the tip after aspiration
and dispensing due to the properties of the resin that the
tip is made. Low retention pipette tips are manufactured
in two ways: from material that is hydrophobic or
batch coated with a hydrophobic material. Typically
manufacturing from a hydrophobic material is superior.
Batch coating can be variable among tips negatively
impacting precision.
LOW RETENTION
Figure 7. Pipette Tip With Low-Retention Technology
Sterile tips are treated with radiation to eliminate
living organisms. They are packaged and shipped in
individual boxes. DNase/RNase-, endotoxin-free tips
undergo additional rounds of sterilization to remove all
contaminants. These tips are typically used for highly
sensitive experiments, such as PCR.
A cheaper alternative to purchasing pre-sterilized tips
is to purchase tips in bulk, and sterilize the racked tips
using an autoclave. This is most useful for tips to be
used in less sensitive, routine applications.
STERILE AND DNASE/RNASE FREE
Figure 8. Sterile, Pre-Racked Pipette Tips.
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THE BIOTIX GUIDE TO PIPETTING
FINDING THE RIGHT PIPETTE TIP
Graduated tips contain measurement markings on
the side of the tip. They enable the user to visually
determine that the right volume is aspirated each time.
These graduations are not exact but can help avoid
large mistakes.
Many other tip types are available for specialty
applications. For example, wide orifice/bore tips have
larger openings for pipetting more viscous fluids.
Gel loading tips contain a thinner drawn out tip for
accessing wells.
GRADUATED TIPSOTHER TYPES
Figure 9. Image of Gel-Loading Tip
SELECTING THE BEST TIP FOR YOUR LAB
1. Do you need a specific pipette type for your pipette? Check around there may be multiple companies selling pipette tips compatible with your pipette.
3. Are you performing PCR or a highly sensitive application? Sterile, DNase free/RNase free barrier tips would be the best choice to prevent carry-over and contamination.
2. Are you working with sticky samples such as protein or DNA? You may want to consider low retention tips
4. Are you working with hazardous samples such as human blood, radioactive, or corrosive material? A barrier tip that seals will protect your pipette from contamination.
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THE BIOTIX GUIDE TO PIPETTING
FINDING THE RIGHT PIPETTE TIP
CHAPTER 4
CARING FOR AND MAINTAINING YOUR PIPETTE
How you store your pipette when it’s not in use is just as
important as how you use it. For example, using a pipette
stand to store your pipettes prevents the instrument from
being accidentally knocked to the ground and keeps your
pipettes organized. Storing pipettes upright prevents any
liquid that might have accidentally been aspirated into the
barrel from running further into the pipette—possibly even
to the piston.
The pipette is a sophisticated and precise piece of
technology that requires proper care and handling.
Dirt, dust, and residual liquids affect its performance.
Your pipette requires calibration on a regular basis to
maintain its precision and accuracy. Most damage to
pipettes arises from improper handling. For example,
the user drops the pipette on the lab bench and
causes damage to the pipette barrel, or incorrect
pipetting technique/pipette tip choice causing
contamination inside the shaft.
PIPETTING TECHNIQUE ADVICE
STORING OF YOUR PIPETTE
Always make sure your movements are smooth and consistent. This prevents jarring of the internal mechanisms of the pipette.
When not using your pipettes, store them upright and away from liquid.
Proper pipetting technique will prevent damage to the piston and other internal mechanisms of the pipette. It will also keep the pipette barrel free from contamination.
Don’t dial a volume that is outside the limits of your pipette (this can also damage internal mechanisms). Use a pipette with a suitable capacity instead.
Always use a pipette stand that fits your pipettes.
Operate your pipette in a vertical position to prevent liquids running along the shaft of the pipette.
Never store your pipettes on their side, and never store them with liquid in their tips.
Don’t let the piston snap back up into place when aspirating—this can lead to liquid backup and contamination of the shaft’s interior.
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THE BIOTIX GUIDE TO PIPETTING
CARING FOR AND MAINTAINING YOUR PIPETTE
Nearly all pipette manufacturers provide cleaning instructions that won’t harm your pipettes. The manufacturer’s
instructions should contain information about safe products to clean the inside of the pipette, and, for example, how
to clean after using radioactive substances. Because certain cleaning products and procedures can harm different
pipettes, be sure to check their instructions before starting any cleaning procedure. However, there are some general
cleaning steps that are helpful for any pipette:
PROPER CLEANING OF YOUR PIPETTES
Wipe pipettes down with a 70 % ethanol solution every day.
Organic solvents (and proteins) can be removed with a detergent solution, as long as the detergent doesn’t damage the pipette.
Learn how to remove the pipette barrel to clean inside (using the manufacturer’s instructions as a guide).
Autoclaving can be helpful, but for some types of pipettes, only certain parts may be sterilized in this way. Always check manufacturer’s guidelines in advance because autoclaving can destroy pipettes that are not suitable for autoclaving!
Visually inspect your pipettes for damage every time you use them.
You can eliminate DNA by immersing pipette parts in at least 3% (w/v) sodium hypochlorite, for at least 15 minutes. Rinse well with distilled water and allow to dry. Some manufacturers have specialized solutions for removing DNA. RNA degrades quickly, and doesn’t require any special treatment to remove.
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THE BIOTIX GUIDE TO PIPETTING
CARING FOR AND MAINTAINING YOUR PIPETTE
CALIBRATION
Calibrating a pipette involves testing it to determine if the dispensed volume is equal to the measured volume. If
those two values aren’t the same, then your pipette needs calibration. All pipettes are calibrated at the factory, but
repeated use (and maintenance issues) call for periodic recalibration. Manufacturers will disclose precision limits
for their pipettes, but these may be more exact than are necessary for your lab. You must determine the necessary
precision for your experiments.
HOW TO CALIBRATE PIPETTES
1. The calibration testing should take place in a draft-free room at a constant temperature between 20°C to 25°C.
5. Repeat step 4 but dispense the second calibration point’s volume.
2. Relative humidity should be above 45%, especially for volumes under 50 µL. Keep the pipette in this room for at least two hours to acclimate.
6. Verify the weights you’ve collected to be within the published pipette manufacturers systematic error range.
3. Choose two points that are published in the user manual by your pipette manufacturer to calibrate against. Nominal and 10% of nominal are usually published.
7. If the volumes fall outside of the published range, you may do the calibration adjustments yourself or send it out to a repair facility.
4. Using distilled water, dispense the first calibration point’s volume onto an analytical balance. Record the weight. Repeat this process ten times.
Calibrations should be done every 6 to 12 months. If you see worn O-rings, they should also be replaced as needed.
Your lab should have a procedure to regularly do self checks in between scheduled calibrations
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THE BIOTIX GUIDE TO PIPETTING
CARING FOR AND MAINTAINING YOUR PIPETTE
Electronic pipettes should be calibrated by the manufacturer or another specialized and trusted facility, because of the
wide variety of features and construction methods for each type of pipette. For manual pipettes, some adjustments can
be made in the lab using the following tips:
CALIBRATION: DO IT YOURSELF OR SEND IT OUT?
All adjustments are made at the lowest volume.
Place the service tool that came with the pipette into the opening of the calibration nut at the top of the handle.
Place the service tool that came with the pipette into the opening of the calibration nut at the top of the handle.
A service tool should have come with the pipette. If one did not, then you can order this from the manufacturer.
After adjusting, check the calibration again using the process outlined above.
www.Calibrate-It.com is a useful resource when carrying out your own calibrations. If these steps don’t help, then send the
pipette out.
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THE BIOTIX GUIDE TO PIPETTING
CARING FOR AND MAINTAINING YOUR PIPETTE
1. Pipette tips drip or leak: This is probably the most commonly encountered pipetting
issue, and can easily occur if tips are loosely fitted, or if inappropriate tips are used. You
can solve this by ensuring that your tips fit your pipettes, and/or by checking the pipette barrel
for damage.
2. The pipette aspirates and dispenses inaccurate volumes: This can occur for a
number of reasons, including pipetting outside the range of your pipette, leaking tips
(see 1. above), or the pipette is in need of calibration.
3. The dispensing button is stiff and doesn’t release smoothly: This may occur if the
seal gets swollen by reagent vapors and can usually be solved by opening the pipette
and allowing it to ventilate. The piston can be lubricated if necessary.
From time to time, your pipette will not behave as it should, and the tips below may help you solve some
of most basic issues you might encounter:
If your pipette stops functioning completely, and the simple tips above don’t help you then don’t
despair, but do send your pipette out for repair!
TROUBLESHOOTING YOUR PIPETTE
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THE BIOTIX GUIDE TO PIPETTING
CARING FOR AND MAINTAINING YOUR PIPETTE
CHAPTER 5
ERGONOMICS AND PIPETTING IN THE LAB
Many scientists do not think about the impact of pipetting on their long-term health. However pipetting has been
identified as a risk for repetitive stress injury (RSI). Ergonomics is the study of how our work and other common
activities affect our physical (in particular our musculoskeletal) health. In the lab, it focuses on how repetitive and
forceful activities, as well as our sitting and standing postures, can cause pain and eventually damage to our bodies.
Much of the work we do in the lab (and many other workplaces) can lead to back pain, RSI and other issues
over time, all depending on the nature of the work. In the lab, we are much more likely to become injured if
we use the wrong equipment, or if we use appropriate equipment in the wrong way.
One common source of RSI and other lab-related work injury stems from pipetting. You may experience RSI
as a numbness around your basal thumb joint, an ache in your wrist, or a general weak feeling in your hand.
These symptoms occur because of the repetitive nature of pipetting and the force you apply when doing
so. The symptoms associated with RSI may also extend into your back and shoulders causing you great
discomfort.
Force in pipetting comes from attaching the pipette tip, dispensing the contents, ejecting pipette tips, and
keeping a tight grip on a poorly designed pipette. Pipetting is usually very repetitive, and any laboratory
worker might go through thousands of pipetting motions every single day. Pipetting for only one hour a day,
over the course of a year, can put you at risk for RSI!
WHY SHOULD WE PRACTICE ERGONOMIC PIPETTING?
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THE BIOTIX GUIDE TO PIPETTING
ERGONOMICS AND PIPETTING IN THE LAB
Older pipette models require a lot of manual force on the plunger and the ejector button, which leads to more muscle
strain than modern pipettes.
CHOOSE AN ERGONOMIC PIPETTE AND ERGONOMIC TIPS
Look for more advanced pipettes that have low profile ejector buttons to reduce ejection force.
Use well-fitting tips such as Biotix with a flexible proximal end (“FlexFit”). This flexing end forms a secure seal with your pipette barrel, eliminating banging or rocking. You should not have to twist your wrist or pound the tip into the end of pipette to get a good fit.
Learn how to remove the pipette barrel to clean inside (using the manufacturer’s instructions as a guide).
Ejection forces can vary greatly between pipette types, so it is important to test and select the one with the least force required.
Figure 10. Demonstration of Flexible Fit at
the Proximal End of the Tip.
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THE BIOTIX GUIDE TO PIPETTING
ERGONOMICS AND PIPETTING IN THE LAB
BE ERGONOMIC – BE KIND TO YOURSELF!PREPARE YOUR WORKSPACE
Keep an eye on your posture. Sit up straight with your arms straight out.
Make sure your work area is clean, clear and organized.
Using proper pipetting technique and practicing good
posture will go a long way in helping you avoid RSI
and other pipetting-related injuries. You can be kind to
yourself by keeping the following in mind:
As mentioned earlier, RSI is only one-lab related injury, and pipetting is only one cause of RSI. Continuous pain or pain that
doesn’t subside when practicing ergonomic pipetting should be addressed by a doctor. From time to time physiotherapy
may be necessary to treat RSI. Luckily, it’s very easy to reduce the risk of pipetting-associated RSI by following the
ergonomic tips provided here. Don’t be afraid to take that 2-minute break!
Take breaks! If you have hours of pipetting work ahead, don’t do a marathon session. Get up, stretch, walk around a little bit, and then start working again.
Make sure you have a waste disposal bucket nearby on the side that suits you best. Position yourself so that you can pipette without
reaching too far. Don’t hunch over or keep your arms elevated for any extended period of time.
Arrange your most commonly used reagents so that you can reach them easily.
Pour liquids into smaller vessels so they are easier to reach, and keep your pipette tips at bench level (don’t try reaching for them up on a shelf).
Remember that the U.S. Occupational Health and Safety Administration (OSHA) recommends taking a 2-minute break every 20 minutes.
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THE BIOTIX GUIDE TO PIPETTING
ERGONOMICS AND PIPETTING IN THE LAB
CHAPTER 6
FURTHERREADING
History of Pipettes:1. Duval C. (1951) Francois Descroizilles, the inventor of volumetric analysis. J. Chem. Educ. 28(10):508–19.
2. The Rockefeller University: Science Outreach Program. Origins of the Pipette: Why Today’s Scientists Don’t Need
to Use Their Mouths.
3. Klingenberg M. (2005) When a common problem meets an ingenious mind. EMBO Reports 6:797-800.
4. JoVE. Introduction to Serological Pipettes and Pipettors.
5. Sella A. (2014) Schnitger’s pipette. Chemistry World.
Pipette Tips:Here are some more references to help with tip selection.
1. Bitesize Bio Biotix article
2. http://biotix.com/technology/
Ergonomic Pipeptting:1. Bitesize Bio Biotix article
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THE BIOTIX GUIDE TO PIPETTING
FURTHER READING