LGC has developed an automated laser plate sealer that utilizes the process of transmission diode laser welding as detailed below. It is able to seal virtually all plate densities from single tubes to 3456 plates.
The ability to seal microtitre plates is perhaps not as straight-forward as it can some time seem. Thermal or adhesive based plates seals are ideal for a number of situations and disciplines. However they have some drawbacks where there is an unmet need. In particular the ability to seal and reseal plates many times and the ability to seal high density plates such as 1536 are areas where conventional heat sealers do not perform well.
Why use a Laser Sealer?
The LGC laser sealer is unique in that the directed laser beam is approximately 75um in diameter. When this is directed onto a plate surface it is directed to the plastic between the wells and not over the wells. This results in very little heat being passed to the plate and ultimately the sample. A number of advantages are enabled by this fact
- No heat is passed to the sample
- Higher plate densities are sealed perfectly
- The seal can be covalent or removable
- The seals that are applied can be optically clear, increasing signal
- Plates can be sealed multiple times (up to 50 !)
The Fusion laser sealer from LGC is a completely automated instrument which can also be controlled remotely via an RS232 command set. The instrument utilizes a 30w 808nm laser that is mounted onto an XY robot allowing the user to program the welding pattern required. It is a bench mounted instrument that requires 5bar compressed air and a single 230v (or 110v) power supply.
How does it work?
Principle of transmission diode laser welding:
Direct diode transmission laser welding relies on the fact that a joint, whose strength often exceeds that of the parent materials, can be produced between two plastic components.
One component part transmits the laser energy and the other part absorbs it. As a result, heat is generated at the surface of the joint interface to a depth of 20 µm, the plastic is melted and fusion takes place. Unlike conventional laser welding, the energy is delivered
to a small 80µm diameter spot creating a uniquely strong weld. This principle is modulated in the Fusion instrument by the choice of seal. Fusion seals are able to covalently seal all black plates with clear films, and utilizing dissimilar materials are able to create peelable seals. By the nature of the fact that 808nm absorbent material is required to create a seal, the Fusion is currently not able to seal a clear plate with a clear seal, although this is being worked on presently.