Labware - Hints and tips

Introduction

This article contains some useful information when using Labware in the SQWERTY pipetting robot. This article may also be helpful : Labware and Pipette Tips Information

Content

• When to change labware
• Tube recommendations
• Labware - General
• Labware - Material
• Volume
• Buying Pipette Tips - Advice

Hints and tips

When to change labware

Making changes to your labware could make your automated workflow more effective (e.g. switch out 15 mL Falcon tube for a 20 mL reservoir, or switch from flip to screw-capped tubes). Labware consistency in automation also makes troubleshooting far easier and improves reproducability.

Tube recommendations

Screw cap tubes are usually preferred over flip cap Eppendorf tubes. The position of a flip cap within an automated liquid handler cannot be accounted for, introducing the risk of the pipette tip crashing into the cap. A screw cap can be completely removed and taken out of the equation. Eppendorfs also have little neck around the upper rim, making it much more difficult to predict the maximum depth.

Flip caps can still be used if you must, but we would recommend cutting off the flip caps or positioning the caps in such a way that they are out of the path of the pipette tip. This still won't mitigate against a crash completely though.

Labware - General

Labware refers to the various containers that the liquids will reside in throughout your workflow. The right kind of labware can go a long way towards ease of use, especially in automated workflows. For large volumes in a manual workflow you might choose a Falcon tube. Makes sense, it's easy to mix and sterile. In an automated workflow the pipette tip would not reach the bottom of a 50 ml Falcon tube, the pipette module would crash into the top of the tube. Reservoirs are the top choice, these are wider than they are deep allowing the pipette tip to access all of the liquid within.

SBS-format skirted plates are needed to securely fit into the zones. Again, quality is important here as the plates should be flat and even. If the plates are being heated at any point during the workflow (e.g. PCR) ensure the plates are still flat after heating. Some have more rigid frames to cope with this, others warp.

Labware - Material

You should also be aware of what material the labware is made out of. The material can effect how the liquid contained will interact with the labware and thus the fluid dynamics during transport or mixing. This could be to your benefit, choosing a hydrophobic tip to transfer liquids with high adhesion for example. Or the material could affect the labware's suitability for a particular application: some multi well plates use more rigid plastic which prevents warping during the heating element of whole plate PCR.

Volume

Volume should also be considered when choosing labware.

Recommended Labware type:

• Reservoir  = >2 ml
• Universal Tube (Screw top) = 250 - 2000 μl
• Multi-well plate = <250 μl

If the tip has no need to go past 0 mm in Z then the object used could be a different shape or volume to the actual labware. As long as the x/y positioning is the same any generic object file for that type of labware will do. However as soon as the tip needs to dip deeper into the labware, be it for a mix or to aspirate, the object file used needs to be more accurate.

Buying Pipette Tips - Advice

It is recommended that pipette tips are ordered from our list of recommended suppliers. All tips used should be ISO 9001 certified; this means that the manufacturer produces high-quality products and consistently so. All recommended suppliers are certified as such.

There are other knock-off brands available that may be cheaper initially but it may affect the ability to complete the experiment successfully. Waviness or wrinkles in the plastic can result in changes to air displacement and to liquid adherence. Burrs or plastic flash inside the pipette tip leads to unintended liquid retention and lower volumes being dispensed. If a batch of tips isn't consistent throughout, the shape of the tip could be affected which would create accuracy and precision problem.

Even the cone of the tip (where the tip adapter is seated) being slightly different from the original dimensions can result in a bad seal creating more pipetting issues or even the tips falling off.

If you require more information please contact [e-mail] for assistance.