Z-Factor Analysis

Calculating the Z-factor for an assay produces a statistically derived, dimensionless value that can be used to characterize the quality of an assay during assay optimization and validation. The Z-factor indicates whether the assay has sufficient dynamic range and low enough data variability to generate meaningful data.

  1. Set up an analysis on the image using the controls in the Plate and Well groups on theICW Analysis tab (see In-Cell Western Analysis).

  2. Choose a normalization channel in which a housekeeping protein or protein stain is detected. The values from the other channel are divided by the values from the normalization channel to account for variations in cell number between wells.
  3. Click the Well Types button to open the Well Types dialog.

    4. Image Studio 5.0 In-Cell Western Well Types dialog

  4. Click Z-Factor Analysis in the Well Legend. The dialog changes to accommodate a Z-Factor Analysis.

    5. Image Studio 5.0 In-Cell Western Well Types dialog with Z-Factor Analysis applied

  5. Select the type of well to mark by clicking the name in the Well Legend.
  6. Click the well to assign the selected well type to that well.
  7. Make multiple well assignments by dragging through the desired wells.
  8. Click OK.

The Z-factor calculation appears in the Definition group. For a description of the calculation, see Calculation Descriptions.

The options in the Expanded ICW Definition dialog are not available for Z-factor analysis.