Rapid Tests

TB Antibody Rapid Tests

Ab: antibody; Ag: antigen;  EC: EC-marked; S: Serum; Se: Secretes; P:Plasma; WB: Whole Blood

TB Antigen Rapid Test

For the qualitative determination of specific antigen of M. tuberculosis secreted in culture broth, human serum/plasma or pleural effusion.

M. tuberculosis Antigen Rapid Test

 

INTENDED USE:

The M. tuberculosis Antigen Rapid Test, is an immune-chromatographically assay intended for the qualitative determination of specific antigen of M. tuberculosis secreted in culture broth, human serum/plasma or pleural effusion.

INTRODUCTION:

Tuberculosis (TB) is caused by repeated exposure to airborne droplets contaminated with a rod-shape bacterium, Mycobacterium tuberculosis. More than 8 million new cases of Tuberculosis have been diagnosed each year and are responsible for more than three million deaths per year. Almost two and three quarter billion people (2.75 billion) or 33% of population are latently infected with TB.

At present, the clinical check (X-ray) coupling with the microscope examination and specimen bacterial culture is the major diagnostic method for the tuberculosis. However, this often takes 4-6 weeks, and the results sometime inaccurate. Among screening infectious diseases, a rapid and accurate diagnostic method of tuberculosis is very important for human health maintain and the disease control.

The M. tuberculosis Antigen Rapid Test shows superior performance for detecting specific secreted antigens of M. tuberculosis from human body fluids.


PRINCIPLES OF THE ASSAY:

Capture of specific antigen in the sample:

Individual with activated M. tuberculosis infection produces secreted antigens in body fluids. Our rapid test is to qualitative the specific TB antigens. This is accomplished by lateral flow sample on nitrocellulose membrane which coated with primary anti-TB antibody. The antigens will bind specifically to the gold conjugated antibody on the capture antibody.

KIT CONTENTS:

1.           Cassette（one cassette for one test）

2.           Desiccant

3.           Dropper

4.           Instruction manual.

MATERIALS REQUIRED BUT NOT PROVIDED:

1.           Drops: capable of delivering from 2 ml to 3 ml volumes.

2.           Timer: for count down.

PRECAUTIONS:

1.           Safety considerations:

1)           Please refer to the manufacturer‘s safety data sheet and the product labeling for information on potentially hazardous components.

2)           If the specimen is culture broth, must be operating in the negative pressure lamina flow.

3)           Do not pipette by mouth. Avoid contact with skin and mucous membranes. Avoid splashing and generating aerosols.

4)           Do not eat, drink, or smoke in areas in which specimens are handled.

5)           Wear disposable gloves throughout the test procedure. Dispose of gloves in the biohazard waste. Wash hands thoroughly afterward.

6)           Dispose of all specimens and materials used in the M. tuberculosis Antigen Rapid Test procedure in the biohazard waste. The recommended method of disposal is to disinfect by autoclaving for 1 hour at 121°C followed by incineration.

2.           Performance considerations:

1)           Do not use kit beyond the expired date.

2)           Do not open foil pouch until it is ready to be tested.

STORAGE INSTRUCTIONS:

1.           Store M. tuberculosis Antigen Rapid Test kits at 4 to 30°C.

2.           The device is stable through the expiration date printed on the sealed pouch.

3.           Avoid storing kits and specimens in auto-defrost refrigerators.

4.           The device must remain in the sealed pouch until use.

PREPARATION:

1.    Bring the cassette and sample to room temperature (21-25°C).

2.    Thoroughly mix the sample before used.

3.    If the specimen is culture broth, must be operating in the negative pressure lamina flow

PROCEDURE:

1.       Prepare all materials and sample back to room temperature (21-25°C).

2.       Remove the test card from the sealed foil pouch, and place it flat on a dry surface.

3.       Place the transfer pipette in the sample and depress the bulb to withdraw the sample.

4.       Sample Loading:

    A. Culture Broth: Add three drops (~150μL) of the sample to the loading sample zone

    B. Human Serum/Plamsa: Add one drop serum/plasma (~50μL) to the loading sample

      zone and load one drop deionized H2O (~50μL) intermediately to the same zone.

5.  As the test begins to work, you will see purple-red color move across the reading window

    in the center of the test device.

6.  Read the results between 20 to 25 minutes. (Please do not interpret the test result over 25 minutes).

RESULTS:

Interpretation of Results:

Positive:

Two colored bands form. The appearance of two colored bands, one in test zone and the other in control zone, indicates positive results.



Negative:

One colored band forms. One colored band appears in control zone. No colored band is found in test zone.



Invalid:

If there is no colored band in control zone, the test result is invalid. Retest the sample with a new kit.



If the result of the human serum/plasma or pleural effusion is positive, for confirmation of Tuberculosis, further examination on clinical symptoms is necessary.

PERFORMANCE CHARACTERISTICS:

Analytical Specificity (Cross-Reactivity) ：

To determine the analytical specificity of the M. tuberculosis Antigen Rapid Test, 18 mycobacterial species’ culture broths were tested. The result showed all strains of BCG and in environmental isolates with the exception of M. kansasii and M. marinum are obtained negative results. But the two species can be separated from M. tuberculosis by morphology.  

Species                 (Results of TB Antigen Rapid Test )
TB complex
M. tuberculosis        (+) 
M. africanum           (+)
M. bovis                  (+)
BCG sub-strains
  gothenburg            (-)
  danish                  (-)
   moreau                (-)
   pasteur                (-)
   tokyo                   (-)
Atypical Strains
M. abcessus          (+)
M. avium                (+)
M. celatum             (-)
M. chelonae           (-)
M. intracellulare     (-)
M. kansasii           (-)
M. malmoense      (-)
M. marinum          (-)
M. smegmatis      (-)
M. xenopi             (-)

EVALUATION RESULTS:

The comparison of identification methods:

In the methods comparison, total 100 samples were tested. The sensitivity of the M. tuberculosis Rapid Test in comparison to PCR and traditional method is 100% (67/67) and 100% (68/68). And the specificity is 78.8% (26/33) and 81.3% (26/32) compared to PCR and traditional method, respectively.

The only one false negative M. tuberculosis isolate in PCR is further confirmed as a genetic mutant.

LIMITATIONS OF USE:

1.           M. tuberculosis Antigen Rapid Test is not used for individual who has taken antibiotics for the TB therapy.

2.           The user of this kit is advised to carefully read and understand the package insert. Strict adherence to the protocol is necessary to obtain reliable test results

3.           The results of rapid test performed on sample from immunosupressed patients must be interpreted with caution.

4.           Samples that remain equivocal after repeat testing should be retested by an alternate method. If results remain equivocal upon further testing, an additional sample should be taken.

5.           Results of this test should be interpreted by the physician in the light of other clinical findings and diagnostic procedures.

6.           Icteric, lipemic, hemolyzed, or heat inactivated sera may cause erroneous results and should be avoided.

7.           Kit procedures or practices outside those in this package insert may yield questionable results.

8.           The performance characteristics have not been established for matrices other than culture broth, human serum/plasma and pleural effusion.

Advantages:

• direct identification of TB antigen
• 
  sensitivity and specificity >99%
• 
  simple procedure and easy to use
• 
  receiving results within 10-15 minutes
• 
  quicker and cheaper than PCR
• 
  test will not be effected by other factors

BIBLIOGRAPHY:

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2.         Chaparas SD, Maloney CJ, Hedrick SR (1970), Specificity of tuberculins and antigens from various species of mycobacteria. Am Rev Respir Dis 101, 74-83

3.         Colangeli R, Spencer JS, Bifani P, Williams A, Lyashchenko K, Keen MA, Hill PJ, Belisle J, Gennaro ML (2000), MTSA-10, the product of the Rv3874 gene of Mycobacterium tuberculosis, elicits tuberculosis-specific, delayed-type hypersensitivity in guinea pigs. Infect Immun 68, 990-993

4.         Dalovisio JR, Montenegro-James S, Kemmerly SA, Genre CF, Chambers R, Greer D, Pankey GA, Failla DM, Haydel KG, Hutchinson L (1996), Comparison of the amplified Mycobacterium tuberculosis direct test, Amplicor MTB PCR, and IS6110-PCR for detection of MTB in respiratory specimens. Clin Infect Dis 23, 1099-1106

5.         Dannenberg AM (1993), Immunopathogenesis of pulmonary tuberculosis. Hosp Pract 28, 51-58

6.         Harboe M, Oettinger T, Wiker HG, Rosenkrands I, Andersen P (1996), Evidence for occurrence of the ESAT-6 protein in Mycobacterium tuberculosis and virulent Mycobacterium bovis and for its absence in Mycobacterium bovis BCG. Infect Immun 40, 908-912

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9.         Noordhoek GT, Kolk AH, Bjune G, Catty D, Dale JW, Fine PE, Godfrey-Faussett P, Cho SN, Shinnick T, Svenson SB (1994), Sensitivity and specificity of PCR for detection of Mycobacterium tuberculosis: a blind comparison study among seven laboratories. J Clin Microbiol 32, 277-284

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11.     Snider DE (1982), The tuberculin skin test. Am Rev Respir Dis 125, 108-118

12.     Trajkovic V, Natarajan K, Sharma P (2004), Immunomodulatory action of mycobacterial secretory proteins. Microbes Infect 6, 513-519