As we saw previously a worklist is essentially a TXT or CSV file with information (commands consisting of individual lines or records with data and instructions) to the liquid handler machines. For the Tecan worklist you have seven different record types available: Aspirate, Dispense, Wash Tips / Replace DITIs, Flush, Break, Set DITI Type and Comment.
Each record starts with a single character indicating the type and is followed by one or more parameters. The parameters are separated by semicolons. As you will see, some of the parameters are optional and some record types have no parameters

Exporting a Tecan worklist from BUILD module results in a TXT file following this format:

A = Aspirate.
D = Dispense.
Position = Well Number (not x,y or alphanumeric coordinates, see below).  Volume = transfer volume in μL.

Let’s take a closer look at each Tecan worklist’s record types: 

  • The Aspirate record has the following structure: A;RackLabel;RackID;RackType;Position;TubeID;Volume;LiquidClass;TipType ;TipMask;ForcedRackType
    Each Aspirate record specifies the aspiration parameters for a single tip (the next unused tip from the tip selection you have specified). 
  • The Dispense record has the following structure: D;RackLabel;RackID;RackType;Position;TubeID;Volume;LiquidClass;TipType ;TipMask;ForcedRackType
    Each Dispense record specifies the dispensing parameters for a single tip. It uses the same tip which was used by the preceding Aspirate record.
  • The Reagent Distribution record has the following structure: R;AspirateParameters;DispenseParameters;Volume;LiquidClass;NoOfDitiRe uses;NoOfMultiDisp;Direction[;ExcludeDestWell]*
    AspirateParameters = SrcRackLabel;SrcRackID;SrcRackType;SrcPosStart;SrcPosEnd;
    DispenseParameters = DestRackLabel;DestRackID;DestRackType;DestPosStart;DestPosEnd;
    The Reagent Distribution record specifies the aspiration and dispensing parameters for all of the tips you have chosen (and dispenses the same volume in all of the chosen wells in the destination labware). 
  • Worklist Examples Using Labware Labels:  Use this worklist format if you want to use labware labels to specify source and/or destination positions in the worklist. This is necessary if your instrument does not have a PosID barcode scanner or your labware does not carry barcodes. In this case, you only need to define the following parameters in an Aspirate or Dispense record:

    Parameter RackType is optional. If specified, Freedom EVOware checks whether the labware specified with RackLabel has the configuration name specified with RackType. 
  • Worklist example:
    - Aspirates 10.1 μl from well A2 in labware “S1”: A;S1;;;9;;10.1
    - Dispenses 6 μl into well A1 in labware “D1”: D;D1;;;1;;6
    - Dispenses 4 μl into well B1 in labware “D1”: D;D1;;;2;;4
    - Washes the tip / changes the DITI: W;
    - Note that Freedom EVOware counts wells from rear to front and then from left to right and a Microplate, landscape labware has eight wells in each column. Accordingly, well A2 is specified in the above worklist as “9”. 

You can consult the Freedom EVOware Software Manual, 393172. ‘Worklist Command’ (pages 15-36 to 15-41).

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