Test strips for determining coagulation factor activities

A test strip for determining the activity of a coagulation factor of the intrinsic or extrinsic pathway in a blood sample, said strip comprising

• a support,
• a sample inlet port for deposition of a blood sample,
• a reaction area comprising a blood coagulation reagent,
• wherein
• the sample inlet port is connected to the reaction area, and wherein the coagulation reagent comprises the following ingredients:
• plasma deficient in the coagulation factor for which activity is to be measured,
• an ionic citrate source,
• a ionic calcium source, and
• either one or more coagulation contact phase activator reagents and phospholipids or
• a mixture of tissue factor and phospholipids.

An in vitro method for measuring an activity of a coagulation factor of the intrinsic or extrinsic pathway comprising

• (i) contacting an isolated capillary blood sample from a test subject with a 5 composition comprising a coagulation contact phase activator, a coagulation factor depleted plasma, an ionic citrate source, and an ionic calcium source, or alternatively, contacting the sample with a mixture of tissue factor and phospholipids, a plasma deficient in the coagulation factor for which activity is to be measured, an ionic citrate source, and an ionic calcium source;
• (ii) determining the time required for blood coagulation of said sample;
• and
• (iii) correlating said blood coagulation time with a particular activity by comparison with a coagulation function, said the coagulation function representing the relation between coagulation time and the activity of a coagulation factor.