Assays assay plate layout

Maintaining a moderate, consistent pipetting rhythm is the best way to ensure that all samples and standards are treated equally. This is easy to accomplish with tube assays, because relatively few samples can be analyzed per set. Microtiter plates present more of a challenge, because up to 96 wells may be utilized at the same time. One solution developed in this laboratory involves the use of a microtiter plate not coated with reagent - the reservoir plate." An excess of all samples and standards is loaded into the reservoir plate. If 0.10 mL is needed for the inhibition step, for example, 0.15 or 0.20 mL of each solution is added to a pre-determined position in the reservoir plate the excess amount simplifies the next pipetting step. The location of each sample and standard is identified on a plate layout sheet, a map of the reservoir plate previously completed by the analyst (Figure 3). When the reservoir... 

PLATE LAYOUT AND ASSAY UNIT STRATEGIC DECISIONS... 

Plate layout for spot testing in competition assay. 

After the step to maximize immunoreactivity of adducts, the experimental samples and the sample of standard DNA are serialfy diluted in flat-bottomed 96-well plates. These plates are set out to match the layout to be attained in the assay plate. 

The layout of samples and controls configured on a plate during an assay. For example, for a primary screen in 384-well plates, columns 1, 2, 23, and 24 are controls, and columns 3-22 are for individual test compounds, whereas for secondary screening, each row will contain a single compound at varying concentrations. 

This is a common approach. A central LIMS system keeps track of the compounds, layout of plates supplied from compound management and the assays requested for each sample. Scientists track the mapping of samples though the preparation of test plates, sample preparation and analysis with the help of macros (usually programmed in Excel). At the conclusion of the experiment, data is uploaded back into the LIMS system for review and delivery to the requesting scientist. 

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