Sample loading cartridge

A sample loading cartridge for a microfluidic device, the sample loading cartridge comprising:

• a cartridge body comprising a sample reservoir configured to house a volume of a liquid sample;
• a sample port in connection with the sample reservoir and configured to receive the liquid sample;
• an output channel connected to and extending from the sample reservoir;
• and
• a feedback channel connected to the sample reservoir and to the sample port and configured to vent air through the feedback channel as the sample reservoir is filled with liquid sample received from the sample port, wherein
• the cartridge body comprises a detection portion aligned with at least a portion of the feedback channel to enable detection of presence of liquid sample in the feedback channel;
• and
• a flow resistance of the feedback channel is lower than a flow resistance of the output channel to cause the liquid sample received from the sample port to enter the feedback channel when the sample reservoir is full with liquid sample, with substantially no liquid sample entering the output channel.