A device for use in imaging a liquid sample comprises an inlet for accepting the sample, a connection conduit and a detection chamber for detection of the sample, preferably optical detection of the sample. The connection conduit connects the inlet to the detection chamber and contains one or more dry reagents for reaction with the sample as the sample passes through the connection conduit. Specific embodiments include devices arranged for treating a blood sample, in particular lysing and staining the sample. The liquid flow may be driven by capillary effect. The device may further include liquid handling structures arranged for centrifugally driven liquid flow, for example to meter a volume of sample and separate the sample into phases by centrifugation.
