Test Catalog

Test ID: GIP    
Gastrointestinal Pathogen Panel, PCR, Feces

Method Description Describes how the test is performed and provides a method-specific reference

The FilmArray GastrointestinaI Panel is a closed system that performs the chemistry required for isolation, amplification, and detection of nucleic acid from multiple viral, bacterial, and parasitic gastrointestinal pathogens from a single stool specimen of patients suspected to have a gastrointestinal infection. A panel contains reagents in freeze-dried form and is divided into discrete segments where the required chemical processes are carried out. Patient sample and hydration fluid are drawn by vacuum into the panel and then placed into the FilmArray instrument. The detection process operations are automated (nucleic acid purification, first-stage polymerase chain reaction: PCR, second-stage PCR, and melt analysis) and complete in about an hour in this closed system:

-Nucleic Acid Purification:

The sample is lysed by a combination of chemical and mechanical mechanisms and the liberated nucleic acid is captured, washed and eluted using magnetic bead technology.


-First-Stage PCR:

A reverse transcription step is performed to convert viral RNA into cDNA prior to amplification. The purified nucleic acid solution is combined with a preheated master mix to initiate the reverse transcription step and subsequent thermocycling for multiplex PCR.


-Second-Stage PCR:

Products of first stage PCR are diluted and mixed with fresh PCR reagents containing an intercalating fluorescent DNA dye (LCGreen Plus), which is distributed over the second stage PCR array. The individual wells of the array contain primers for different assays (in triplicate) that target specific nucleic acid sequences from each of the pathogens detected, as well as control template material.


-DNA Melting Analysis:

Temperature is slowly increased and fluorescence in each well of the array is monitored and analyzed to generate a melt curve.


-Analysis of Melt Curves:

The software evaluates the DNA melt curve for each well to determine if a PCR product was present in that well. If the melt profile indicates the presence of a PCR product, then the analysis software calculates the melting temperature of the curve, which is then compared against the expected range for the assay. When the software determines that the melt curve is positive and in range, it is called positive. When it determines that the melt curve is negative or is not in the appropriate range, it is called negative.


-Analysis of Replicates:

Melt curves of each of the 3 replicates for each assay are evaluated to determine the assay result. For an assay to be called positive, at least 2 of the 3 associated melt curves must be called positive, and the temperature for at least 2 of the 3 positive melt curves must be similar (within 1 degree C). Assays that do not meet these criteria are called negative.(Instruction manual: FilmArray Gastrointestinal [GI] Panel CE IVD, BioFire Diagnostics, LLC; RFIT-PRT-0143-04 06/2017)

PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Sunday

Report Available The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

1 to 2 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

7 days

Performing Laboratory Location Indicates the location of the laboratory that performs the test