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Lab Manual for UCSF Clinical Laboratories

Lab Manual for SFGH

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Item Value
Available Stat? No
Test code DFVZV
Performed by? Reference Laboratory - ARUP web page for Varicella-Zoster Virus DFA test details.
Sendout? yes
Price range $$$
In House Availability Specimens may be collected at any time. Specimens will be sent to a reference lab for performance of the direct FA. Results will be available within 24-72 hours.
Principle Cellular material from suspicious lesions or ulcers is fixed to a slide and stained with fluorescein-conjugated monoclonal antibodies to VZV. After a rinse to remove excess stain, the slide is examined under a fluorescent microscope for characteristic fluorescence.
Interpretation INTERPRETATION: Positive direct FA indicates the presence of VZV antigen. Negative direct FA may indicate the absence of VZV or may be due to improper specimen collection or the presence of only small amounts of virus.
Slides which contain inadequate cellular material will be reported as "Inadequate smear."

CLINICAL SIGNIFICANCE: The result must be interpreted in conjunction with clinical findings and other laboratory data.
Container type Swab in viral transport medium or swab in a small amount (approx. 0.5 ml) of sterile non-bacteriostatic saline in a sterile tube.
Collection Instructions Collect specimens aseptically as soon as possible after onset of symptoms. Unroof vesicle and scrape the base of the lesion with a swab without inducing bleeding. It is essential to obtain cells.
Sample type Scrapings from vesicles, lesions, ulcers
Special instructions REQUISITION: Microbiology (Viral - Direct FA for Varicella-Zoster Virus)

Deliver to the Microbiology laboratory (2M33 immediately after collection or refrigerate until delivery.
Normal range no antigen detected
References 1. Clarke, LM, ed. 1992. Section 8: Viruses, Rickettsiae, Chlamydiae, and Mycoplasmas; as found in Clinical Microbiology Procedures Manual, H. Isenberg, ed. Amer. Soc. for Microbiol., Washington, D.C.

2. Schmidt, NJ and RW Emmons, eds. 1989. Diagnostic Procedures for Viral, Rickettsial and Chlamydial Infections, 6th ed. Amer. Public Health Assn, Washington, D.C.
CPT coding 87798
Last Updated 1/15/2009 12:50:37 PM
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