Part of the Culex® system is a missed sample detection feature. The sample detection happens at two points during collection. During the sample draw, the sensor looks for blood coming into the reservoir. If it is not there, it will flush and re-try up to 3 times. If the blood is present, it proceeds to delivery. During delivery, the sensor will read the blood throughout the entire process. If there is a change in the properties of the blood, the Culex® will stop the sample, delivering a “short”, but undiluted sample into the vial. The collected volume is recorded in the report.