US · guidance
CMS SOM App. C, Tag D5457
§493.1256 Standard: Control procedures
(d)(4) For thin layer chromatography--
(d)(4)(i) Spot each plate or card, as applicable, with a calibrator containing all
known substances or drug groups, as appropriate, which are identified by thin layer
chromatography and reported by the laboratory; and
(d)(4)(ii) Include at least one control material on each plate or card, as applicable,
which must be processed through each step of patient testing, including extraction
processes.
Interpretive Guidelines §493.1256(d)(4)
For qualitative urine drug screens performed by thin layer chromatography, a negative
control is not required. However, a control containing one or more drugs representative
of each drug group reported (e.g., tricyclic antidepressants, barbiturates) that goes
through each test phase (including the extraction process) is required.
History
Rev. 233; Issued: 09-12-25; Effective: 09-12-25; Implementation: 09-12-25
Provenance
- Source
- cms.gov
- Retrieved
- 2026-07-22
- Edition
- som-2026-07-22
- Content hash
6df47144a8f9d9243c04dcf624428849caccfad63fa279e0f8fb1aaed5963c66
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