SkinnyTube™ 10X Dx™ Viral Transport Medium Tubes and Swab Kit-0.3 ml Fill

SKT-031A-01

SkinnyTube™ 10X Dx™ Viral Transport Medium System is designed for the collection and transport of clinical specimen for the preservation and recovery of viral agents and bacterial and other pathogens for diagnostic testing, with a gain of around 10 times concentration of collected swab samples, relative to the traditional transport medium tube.  

The internal compartment results in around 10X increased diagnostic sensitivity (10X Dx™) by reducing sample dilution while introducing a secondary self-containment system to ensure maximum leakage prevention and safe transport.  This product is filled with 0.3 ml of medium, which when compared with  a conventional transport medium tube filled with 3 ml of medium results a 5 fold increase in concentration of the collected sample. Other SkinnyTube™ 10X Dx™ products with different fill volumes ranging from 0.2-0.6 ml can result in 5-15 X gain in concentration (compared to a conventional fill volume of 3 ml in a conventional tube). 

 

The ready-to-use system combines a disposable SkinnyTube™ transport tube filled with non-inactivating viral transport medium (VTM) and a Puritan® PurFlock Ultra® Flocked Sterile nasal swab for efficient collection and safe transport. Each kit contains 1 SkinnyTube™ 5X Dx™ screw-cap cylindrical contour tube filled with 0.6 ml VTM and 1 Puritan® PurFlock Ultra® Sterile Flocked Nasal Swab. The VTM is stable from 2°C to 4°C with a neutral pH maintained by a buffer solution comprised of antimicrobial agents in addition to sources of protein and sucrose to support virus preservation for up to 48 hours.  

The non-inactivating viral transport medium included in these products is a universal transport medium formulated for virus preservation (Table 1). The key ingredients include:   

Table 1: Transport Medium Composition 

Hank’s Balanced Salts	L-Glutamic Acid
Bovine Serum Albumin	Phenol Red
Gelatin	Colistin
Sucrose	Amphotericin B
L-Cysteine	Vancomycin
HEPES	pH: 7.3 ± 0.2

 

PROCEDURE  

1. Open package containing the Puritan® swab and SkinnyTube™ tube filled with VTM.
2. Open the sterile swab pouch and collect the specimen without bending the nasal swab as directed by Puritan®. 
3. Unscrew the tube’s cap aseptically and insert swab containing the sample into the media in the inner compartment without touching any other surfaces to prevent contamination.
4. Snap swab at the breakpoint highlighted by the black line using the edge of the tube and appropriately discard of the upper portion of the used swab into a medical waste container. 
5. Align and lower the plunger with the opening of the inner compartment to seal off the medium tube and screw the cap back on to properly seal the tube. 
6. Label the tube containing the specimen using appropriate identifications. 
7. Follow local institutional procedures and send the SkinnyTube™ tube sample to the laboratory for analysis. 

 

SPECIFICATIONS

Designed for compatibility with the Puritan® PurFlock Ultra® Sterile Flocked Nasal Swab with a break point at 30 mm.  

Dimensions:    Tube: 9.0 cm (height) by 5.5 cm (circumference) 

Swab: 153.4 mm handle (length) with 3.429 mm tip (diameter).

Materials:       Tube: Polypropylene tube, silicone inner cap, and high-density polyethylene plastic (HDPE) cap (red) 

Swab: Polystyrene handle and flocked polyester tip. 

 

PERFORMANCE CHARACTERISTICS 

To investigate on the notion of raised analyte concentration in the novel tube compared to that of the conventional tube, the SkinnyTube™ with 0.3 ml of Hanks-balanced salt-based medium was compared to the conventional tube with 3 ml of Hanks-balanced salt based medium.  

A total of 36 swabs were tested. Each of the 36 swabs was dipped into a spiked mock sample containing a SARS-CoV-2 RNA (COVID-19 viral RNA). Then each of 18 dipped swabs was placed into a separate SkinnyTube™ (novel tube); each of the other 18 swabs were placed into a separate conventional tube. 100uL of the transport medium from each of the 36 tubes was removed, heated, and then tested in a duplex SARS-CoV-2 quantitative reverse transcription polymerase chain reaction (RT-qPCR).  

A duplex SARS-CoV-2 RT-qPCR tested 2 regions (N1 and N2 regions of the N gene) of the viral SARS-CoV-2 RNA to further validate the assay results. The cycle threshold (Ct) values from the RT-qPCR are listed below in Figure 1. The results showed that the average Ct value for N1 Region for the novel tube was 29.6 or was 3.1 less than that for the conventional tube (average Ct 32.7). Since Ct is a direct reflection of the analyte concentration, this difference corresponds to 8.5-fold more viral RNA analyte concentration in the novel tube than that for the conventional tube. The difference of average Ct value for N2 Region between the two groups of tubes was 4.7 (average Ct 35.5-30.9), corresponding to 25-fold viral RNA analyte concentration in the novel tube than that for the conventional tube. This > 10-fold increase in the viral RNA analyte concentration for N2 test was probably because when the assay result was near 37, the errors in Ct were inherently greater.  

The N2 Region assay data showed that 5 of 18 (28%) samples were not even detectable (Ct<45 or 43 as criterion) in the conventional tube group, whereas all 18 samples in the novel tubes were detected. This suggests that the novel tubes are particularly more useful in the detection of low concentration (low positives near cut-off of an assay) samples .

 For more information, please visit: skinnytube.ca. For research use only