Monthly Archives: May 2012

Window Shopping for e-pipettes

One of the most important parts of any good experiment is to have high quality equipment, stands to reason. It’s important to have the best quality equipment you can get (afford).  The big instruments that do the heavy duty analysis go out to tender and have maintenance contracts on them, so you can generally rest easy that they’ll be doing the right thing.  The smaller bits and pieces can have a bigger impact on results than you might expect.

One of the key pieces of preparatory equipment in the biology laboratory is the micro-pipette.  It’s a straightforward enough concept, you jam a disposable tip onto one end and the pipette can suck some of the volume out of the tip and thus suck up liquid.  The pipettes are callibrated so you can suck up and dispense very specific and tiny amounts of liquid.

Manual pipettes such as this on the right:

gilson pipette

A gilson manual pipette. Great pipette but terrible on arthritic thumbs.

rely on a spring to move the piston in the pipette to a “sucked up” position. So to empty the tip of air or liquid, you have to press against this spring. Then to suck up the air, you slowly release the pressure to prevent liquid getting sucked up too fast (this is a particular problem with viscous fluids like glycerol).

Working against this spring can be hell on your hands if you have arthritis (or RSI for that matter, which you’ll get from doing too much pipetting).  Electronic pipettes remove this spring problem and use something like a stepper motor instead to move the piston.


I’m currently on the hunt for a set of Good electronic pipettes, that cover the same range of volume dispensing as the manual ones but with a similar or better accuracy/precision.  Despite there being no electronic single channel (multichannel can take many tips and are dead handy) in any of the nearby laboratories, there are a plethora available online, so now the fun part is deciding which ones balance accuracy and precision with cost and ease of use.


A bit of background

There are many types of arthritis, juvenille, rheumatoid, osteoarthritis, psoriatic…..  Arthritis is characterised by an inflamation affecting the joints.  This can lead to pain and stiffness and can lead to long term damage and disability.

Arthritis can affect people of all ages, but predominantly tends to affect women post-puberty and post-menopausal.  You might notice that these are times of major hormonal shift, and many autoimmune diseases such as lupus and arthritis manifest about these times, in fact, many autoimmune diseases are found at a much higher incidence in women.

Knowing this background, my arthritis is relatively “normal”. I was diagnosed when I was about 26, and yes, I am female.

I am also a scientist.

Continue reading