CMS SOM App. C, Tag D5453

(d)(3)(iv) Each test system that has an extraction phase, include two control

materials, including one that is capable of detecting errors in the extraction process;

and

Interpretive Guidelines §493.1256(d)(3)(iv)

Bacteriology:

For direct antigen systems, laboratories may use bacterial cell suspensions to meet the

requirement for control organisms since the cell suspensions are subjected to both the

extraction and reaction phases of the test. However, a matrix similar to patient specimens

is preferred. For example, for direct antigen tests for group A streptococcal antigen,

commercially prepared, dried (solid-shafted) swabs, one containing group A

streptococcus (S. pyogenes) as a positive control and another with non-group A

streptococcus and/or Staphylococcus aureus as a negative control may be used.

Additionally, if the manufacturer’s instructions do not specify what the positive control

contains, the laboratory should contact the manufacturer to ensure that the positive

control contains a cell suspension of the organism. Otherwise, the laboratory must have

an alternative mechanism for meeting this requirement (e.g., laboratory suspension stock

American Type Culture Collection (ATCC) organism, commercially prepared organism

controls).

Toxicology:

For comprehensive broad spectrum qualitative drug screening, procedures using gas

chromatography, a control material containing one or more drugs representative of each

drug class reported (e.g., tricyclic antidepressants, barbiturates), must go through each

test phase, including the extraction process.

NOTE: For gas chromatography and mass spectrometry used for drug confirmations, an

analyte-specific control is required for both qualitative and quantitative tests.