Section 864.7925 - Partial thromboplastin time tests(a)Identification. A partial thromboplastin time test is a device used for primary screening for coagulation abnormalities, for evaluation of the effect of therapy on procoagulant disorders, and as an assay for coagulation factor deficiencies of the intrinsic coagulation pathway.(b)Classification. Class II (performance standards).45 FR 60629, Sept. 12, 1980