High CV from Inconsistent Well Washing

Symptom

High coefficient of variation (>15%) between replicates with uneven background signal across the plate. Some wells show higher background than others after washing steps.

1. 1 Wells not washed equally or thoroughly during wash steps
2. 2 Plate washer nozzles are clogged or misaligned, causing uneven aspiration
3. 3 Manual washing with single-channel pipettor leads to inconsistent technique
4. 4 Insufficient wash buffer volume or inadequate number of wash cycles
5. 5 Plate washer vacuum pressure not properly calibrated

1. 1 Always wash wells exactly as recommended in the protocol (volume and number of cycles)
2. 2 Check that the plate washer is functioning properly and has been recently cleaned
3. 3 Use a multi-channel pipettor when washing plates manually to ensure equal treatment
4. 4 Perform regular maintenance and cleaning of automated plate washer nozzles
5. 5 Verify vacuum pressure settings meet manufacturer specifications

Related Video (2)

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