Laboratory Test Guide

Plasmodium 18S rRNA quantitative RT-PCR assay

General Information

Lab Name

Plasmodium 18S rRNA Quantitation

Lab Code

MAL18S

Description

The assay is a quantitative molecular reverse transcription PCR assay to detect and measure 18S rRNA from Plasmodium parasites and to specifically identify Plasmodium falciparum. The assay detects 18S rRNA from parasites in infected red blood cells and from gametocyte stage parasites.

Quantitative results are reported as 18S rRNA log10copies per milliliter of whole blood. For P. falciparum, the copies/mL result can be converted to estimated parasites/mL using a conversion factor of 7400 copies/ring-stage P. falciparum parasite. This conversion factor does not exactly apply to non-P. falciparum species (P. vivax, P. ovale, P. malariae, P. knowlesi) because of the presence of ring, trophozoite and schizont stage parasites in peripheral blood.

Synonyms

Malaria molecular nucleic acid test

Components

Code	Name
M18SDE	Plasmodium 18S rRNA Specimen
PF18R	Plasmodium falciparum 18S rRNA Result
PAN18R	Pan Plasmodium 18S rRNA Result
M18INP	Plasmodium 18S rRNA Interpretation
M18MTH	Plasmodium 18S rRNA Method

Interpretation

Method

Real-time reverse transcription PCR

Reference Range

See individual components

Guidelines

Washington DOH Notifiable Conditions

Ordering & Collection

Specimen Type

EDTA blood

Collection

Preferred: EDTA Lavender Top Tube

Note: Should be a dedicated tube (NOT shared with other tests except for MALP)

Unacceptable: Heparin (Green top) and Red Top Tube.

Handling Instructions

Whole blood in EDTA (lavender top) can be stored at room temperature or at 4°C and should be transported to the Laboratory as soon as possible, ideally within 4-6 hours but no later than 48 hours after collection. If samples cannot reach the lab within 48 hours, samples should be stored at ≤-70°C within 4 hours and later transported to the MMDL on dry ice.

Quantity

requested: 2.0 mL EDTA blood.
minimum: 0.2 mL for infant; 0.5mL for adult.

Processing

Contact Malaria Molecular Diagnostic Lab at 206-685-8212 or 206-685-4599 for incoming specimens. If specimens can be reached to the lab at UWMC South Lake Union Campus within 4-6 hours of collection, ship the specimen with ice packs. If not, store the specimen in a -80°C freezer within 4 hours of collection and then send the specimen on dried ice.

Testing is performed at the Malaria Molecular Diagnosis Lab (SPOT = HMMDL) which is located at 750 Republican St, Building F, Room F891G, Seattle. All samples originating at facilities other than UWMC-ML should be sent to UWMC-ML SPS. UWMC-ML SPS staff will then send the sample(s) via Reference Lab Courier to the South Lake Union UW Neighborhood Clinic where they will be held until picked up by the MMDL staff.

Performance

LIS Dept Code

Malaria Molecular Diag Lab (MMDL)

Performing Location(s)

Other	Malaria Molecular Diagnostic Laboratory 206-685-8212 Malaria Molecular Diagnostic Lab University of Washington Bldg F - F891G 750 Republican St Seattle, WA 98109	206-685-6162 (office)