CMS SOM App. C, Tag D5411

materials, and supplies.

(a) Test systems must be selected by the laboratory. The testing must be performed

following the manufacturer’s instructions and in a manner that provides test results

within the laboratory’s stated performance specifications for each test system as

determined under §493.1253.

Interpretive Guidelines §493.1252(a)

The laboratory must meet any and all regulatory requirements and comply with the

manufacturer’s requirements to the extent that the manufacturer’s requirements do not

conflict with any regulatory requirements. We encourage laboratories to also comply

with the manufacturer’s recommendations for testing to the extent that the manufacturer’s

recommendations do not conflict with any regulatory requirements.

These include, but are not limited to:

• Handling reagents, materials, and supplies;

• Adhering to conditions for storage and testing; and

• Performing equipment maintenance and function checks

For International Normalized Ratio (INR) calculation, ensure the laboratory:

• Verifies that the normal patient Prothrombin mean study has been performed

according to the manufacturer’s instructions;

• Periodically verifies, for each thromboplastin lot number in use, the correct

normal patient Prothrombin time mean and the International Sensitivity Index

(ISI) value are being used for calculating the INR value; and

• Periodically verifies the accuracy of the INR calculation (manual, instrument or

LIS).

To verify Prothrombin time testing with INR calculations:

• Check the accuracy of normal Prothrombin time mean calculation (manual,

instrument or LIS).

• Verify the ISI used in the calculation correlates with the ISI specified in the

reagent package insert. Select an abnormal low or abnormal high Prothrombin

time result and verify the calculation.

For Immunology tests such as Syphilis Serology, check for the following parameters:

• Antigen volume;

• Incubation time and temperature;

• Light source;

• Rotator speed and circumference; and

• Conjugate titer.

Probes §493.1252(a):

Are instruments with adjustable settings appropriately set for each substance or cell to be

analyzed (e.g., gamma counters, flow cytometry)?