Maintaining the quality and integrity of your DNA samples in the lab is crucial to successful PCR, as there are multiple factors at play to ensure you end up with a high yield of amplified DNA once PCR is completed.
 
Without proper liquid handling techniques (see Labnet’s Pipette Best Practices), you run the risk of an incomplete mixture of your specific reaction reagents and DNA samples, leading to a reduction in the quality and quantity of your PCR yield.