synthesis of HCY will take place in red blood cells after sampling. Samples should be stored on ice between the time of sampling and centrifugation. Note that storage on ice makes the use of serum samples particularly difficult.

The use of an ultracentrifuge is recommended to clear lipemic samples.

Hemolyzed samples may indicate mistreatment of a specimen before receipt by the laboratory; hence the results should be interpreted with caution.

Centrifuging serum samples before a complete clot forms may result in the presence of fibrin. To prevent erroneous results due to the presence of fibrin, ensure that complete clot formation has taken place prior to centrifugation of samples. Some samples, particularly those from patients receiving anticoagulant therapy, may require increased clotting time.

Blood collection tubes from different manufacturers may yield differing values, depending on materials and additives, including gel or physical barriers, clot activators and/or anticoagulants. IMMULITE 2000 Homocysteine has not been tested with all possible variations of tube types. Consult the section on Alternate Sample Types for details on tubes that have been tested.

Volume Required: 15 µL plasma or serum.

Storage: 14 days at 2–8°C, or 6 months at –20°C.

Warnings and Precautions

For in vitro diagnostic use.

Reagents: Store at 2–8°C. Dispose of in accordance with applicable laws.

Follow universal precautions, and handle all components as if capable of transmitting infectious agents. Source materials derived from human blood were tested and found nonreactive for syphilis; for antibodies to HIV 1 and 2; for hepatitis B surface antigen; and for antibodies to hepatitis C.

Sodium azide, at concentrations less than

0.1g/dL, has been added as a preservative. On disposal, flush with large volumes of water to prevent the buildup of

potentially explosive metal azides in lead and copper plumbing.

Chemiluminescent Substrate: Avoid contamination and exposure to direct sunlight. (See insert.)

Water: Use distilled or deionized water.

Materials Supplied

Components are a matched set. Labels on the inside box are needed for the assay.

Homocysteine Bead Pack (L2HO12) With barcode. 200 beads, coated with S-adenosyl-L-homocysteine (SAH). Stable at 2–8°C until the expiration date. L2KHO2: 1 pack.

Homocysteine Reagent Wedge (L2HOA2)

With barcode. One wedge, containing 3 reagents: 15.5 mL bovine S-adenosyl-L- homocysteine hydrolase in buffer, with preservative. 18.5 mL dithiothreitol (DTT) in buffer. 11.5 mL alkaline phosphatase (bovine calf intestine) conjugated to murine monoclonal anti-SAH in buffer. Stable at 2–8°C until expiration date. L2KHO2: 1 wedge.

Before use, tear off the top of the label at the perforations, without damaging the barcode. Remove the foil seal from the top of wedge; snap the sliding cover down into the ramps on the reagent lid.

Homocysteine Adjustors (LHOL, LHOH) Two amber vials (Low and High), 2.0 mL each, of synthetically-derivedS-adenosyl-L-homocysteine (SAH) in a protein/buffer matrix. Stable at 2–8°C for 30 days after opening, or for 6 months (aliquotted) at –20°C.

L2KHO2: 1 set.

Before making an adjustment, place the appropriate Aliquot Labels (supplied with the kit) on test tubes so that the barcodes can be read by the on-board reader.

Kit Components Supplied Separately

Homocysteine Sample Diluent (L2HOZ) For the on-board dilution of high samples.

25mL of concentrated (ready-to-use) homocysteine-free protein/buffer matrix.

IMMULITE 2000 Homocysteine (PIL2KHO-14, 2007-11-20)

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