When sourcing multichannel pipettes, the most critical factor is volumetric accuracy and precision (CV%) across all channels. You must ensure the device complies with ISO 8655 standards, which define the maximum permissible errors. Look for 360-degree rotating manifolds for ergonomic flexibility and individual piston assemblies that allow for easy maintenance of a single channel without affecting the entire unit. Additionally, verify that the pipette features a low-attachment and low-ejection force mechanism to reduce Repetitive Strain Injury (RSI) for lab technicians.