Static scripting is the easiest to achieve and can typically performed within the vendor-supplied scripting language. However, static scripting is the most inflexible and requires that other portions of the work flow be adapted to fit the script requirements. Our experience with this approach is that additional up-front efforts to create and verify sequence files to the script must be made. If a LIMS system is used, then the analysis sequence file may make use of a template for this purpose. The number of samples can be restricted and dilutions or pooling may not be available. One of the areas to consider is the source of samples for analysis (see earlier). One approach for dynamic scripting, for example, is to develop a custom Visual Basic program that combines aspects of stand-alone application, OLE-automation of GeminiTM software components, and prewritten scripts. The program creates a text file (referred to as the worklisting file) in a delimited format that describes parameters for each robotic step. The software has easy, programmable built-in functions that interpret and execute the commands in the file. The robot requires each of the critical pieces of information to perform a particular command. For example, for an aspiration step the robot must receive the deck-location information, which includes carrier position, rack type and location, tube number, and the pipetting parameters. In a custom program developed in our laboratories, two text files are needed to perform the fully automated cherry-picking routine. The first file is a manifest file that describes the plate and tube location for each uniquely identified sample. The second file is a sequence file that is directly exported from the LIMS and contains sample identification, volume, dilution, tube location, and calibration curve information. The files are parsed and the application automatically creates the worklist file that is semicolon delimited in the following format:
A,D,or W;Rack Label;;Rack Name,-Well #;;volume; liquid class
Where A=Aspirate, D=Dispense, and W=wash For Example:
A;S1;;Matrix w/ Costar tubes, LS;2;;50;Plasma D;D1;;Costar Modular 96 well P;19;;50;Plasma W;
A;S1;;Matrix w/ Costar tubes, LS;10;;5 0;Plasma D;D1;;Costar Modular 96 well P;18;;50;Plasma W;
In addition to the liquid-handling instructions, we have incorporated functionalities such as metrics tracking and error notification by e-mail or paging systems. A similar approach on the Packard™ has been reported .
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