Multi-channel mayhem? Don't blame the tips!

Multi-channel mayhem? Don't blame the tips!

Does your lab have a love/hate relationship with their multi-channel pipette? 

When it comes to increased speed and throughput, short of a fancy robotic system, there is nothing quite like the multi-channel pipette for blazing through the tedium of repeat liquid handling. 

The trouble is, very often those advantages are frustrated when trying to maintain consistency when using the pipette. 

Typically, the problem presents itself in one of two ways:

Either the tips drop off the end of the pipette cone, or, they seem to adhere fine, but it is impossible to draw up the correct volume.

The knee-jerk reaction is to assume that what is going on is an incompatibility with the pipette tip. This would be the case if the end-user is trying to pair a proprietary system, like the Rainin LTS with some other universal tip. 

The truth is, the problem likely has nothing to do with the tip at all. 

In general, the two culprits are user error or an issue with the pipette tip wafer. 

Talking about user error is bound to provoke some hostile reaction. After all, pipetting is so elementary to lab work that to suggest one's technique is wrong could be a grave affront. 

Let's be honest - There is a tendency to solve pipetting issues with brute force. The thinking goes: "if you are not getting a good fit, you are not sufficiently pounding your pipette to form a tight seal." 

Would anyone ever suggest brute force as the correct way to close a stubborn incubator door?

Its a gentle, firm pressure that wins the day. And, its not as easy as you think to learn how to properly rock the tips into place. There are many excellent videos that demonstrate good pipetting technique. Check them out on You Tube.

The second reason your tips do not adhere well depends on the amount of give built into the tip wafer. This is the piece of plastic that is used to support the tips. When working with filter tips or other single-use tips, the plastic base is often sturdy enough to provide adequate resistance so that the combined upward/downward pressure allows the tip to stick to the pipette cone. 

When using a reloadable tip system, these wafers are constructed to be lightweight and can buckle under force and not provide ample rebound, so the tips tend to not attach well. 

In general, if you are having trouble with the tips in the middle of the multi-channel, that is likely a tip wafer problem. If you are having problems with tips on the edge, it might be time for a refresher course! 

Are you in need of a multi-channel pipette? Check out our selection here.