Is there a way to simply sequential dispensing in a 96 well plate, col. by col. changing tips at each time ?

Hello,

Thank you for reaching out with your VWorks question.

In general, you can either perform this as a series of tasks as you have already done or make use of loops and scripting to condense the protocol. As you noted, using loops will continuously dispense to the same well selection made in the task. However, you can make use of the advanced settings and utilize script to allow task parameters to be variable. From here, you can adjust that variable each time it loops - most commonly based on the loop count. 

Scripting this protocol would involve making use of the task object to set the Wellselection parameter of the task before the task itself is executed. 

Task Object User Guide Page: task object (agilent.com). For this example, you likely need to focus on the Wellselection section under the Array data types and apply that to your 

Loop Task User Guide Page: Loop and Loop End (agilent.com). You can configure a variable under custom parameters to automatically iterate each time it loops. 

We also have an old application note that goes over an example of this in a 3 column format - but it could be easily adapted to the single column format you are running. This example also scripts the tips on and tips off tasks, which is not required if you make use of the built in tip tracking feature for VWorks. Still, you could script that step too per this example if desired. 

Thank you,

Andy