Small elution volumes in CA purification

[jgruselius]

Affected protocols:
ca_purification_96_v1202.pro (master), ca_purification_runset_v1202.pro (master),
ca_purification_96_v1202.pro (production), ca_purification_runset_v1202.pro (production)

Description:
When the elution is done with small volumes (seemingly less than 20 µL) there is a risk that the eluate is not transferred from the plate where the beads are collected to the final plate. The reason for this being that the droplet is not in the center of the well and is missed by the tip.

Possible fixes:

• Disable shaking during elution (implemented)
• Manually spin down elatuate before transfer
• Do not allow elution volumes less than 20 µL
• Change plate from current round-bottomed to conical

[jgruselius]

The removal of the shaking step did not solve the issue when elution volume is 17.5 µL. In several wells the droplet is missed by the tip due to being slightly off-center.

[jgruselius]

A pause was introduced in ca_purification_96_v1202.pro. When elution volume is ≤ 24 µL the protocol will pause after adding the elution buffer and instruct the user to spin down the eluate is transferred.