DiaPharma Group, Inc.

Intended use

Automated chromogenic assay for the quantitative determination of Antithrombin in human citrated plasma on the IL Coagulation Systems.

Summary and principle

Antithrombin (AT) or Heparin Cofactor I is the major inhibitor of blood coagulation and is essential for effective heparin therapy. By inhibiting the coagulation proteases, especially thrombin, FXa and FIXa, AT prevents uncontrolled coagulation and thrombosis.

Antithrombin deficiency is associated with a high risk of thromboembolic disorders.

Liquid Antithrombin can be used to exclude or diagnose hereditary deficiency in patients with a tendency toward thromboembolism, in pre-operative stages, before prescription of oral contraceptives, DIC6, nephrotic syndromes, liver diseases7 and in therapy with heparin or antithrombin concentrates.

The Liquid Antithrombin kit is an assay based on a synthetic chromogenic substrate and on FXa inactivation.As a consequence, the method is specific and not influenced by Heparin Cofactor II.

Antithrombin levels in patient plasma are measured automatically on IL Coagulation Systems in two stages:

1. Incubation of the plasma with the Factor Xa reagent in the presence of an excess of heparin.
2. Quantification of the residual FXa activity with a synthetic chromogenic substrate. The paranitroaniline released is monitored kinetically at 405 nm and is inversely proportional to the Antithrombin level in the test sample.

Reagents -- Composition, Packaging, Storage and Stability

Chromogenic substrate (Cat. No. 0020002520): 2 x 2 mL vials of the chromogenic substrate S-2765, N-α-Z-D-Arg-Gly-Arg-pNA.2HCl (6 mg/vial), surfactant and buffer. Opened reagent is stable: 5 weeks at 2-8°C in the original vial, 48 hours at 15-25°C on the ACL® 8000/9000/10000, 8 hours at 15-25°C on the ACL Classic or 48 hours at 15°C on the ACL Futura® and ACL Advance Systems. Do not freeze.

Factor Xa reagent (Cat. No. 0020002510): 4 x 4 mL vials of a solution containing bovine Factor Xa (40 nkat/vial), heparin, buffer, bovine serum albumin and preservatives.Opened reagent is stable 5 weeks at 2-8°C in the original vial, 48 hours at 15°C on the ACL 8000/9000/10000, ACL Futura and ACL Advance Systems or 8 hours at 15°C on the ACL Classic Do not freeze. For optimal stability remove reagents from the system and store them at 2-8°C in the original vial.

Unopened reagents are stable until the expiration date shown on the vial when stored at 2-8°C.

Additional reagents and control plasmas
The following are not supplied with the kit and must be purchased separately.

• Liquid AT Substrate 0020002600
• Calibration plasma 0020000000
• Normal Control 0020003120
• Special Test Control Level 1 0020010100
• Special Test Control Level 2 0020010200
• Low Abnormal Control 0020003220
• High Abnormal Control 0020003320
• Factor diluent 0009757600
• Cleaning solution 0009831700
• Cleaning agent 0009832700