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The BD ProbeTec CT Q^x Amplified DNA Assay, when tested with the BD Viper™ System in Extracted Mode, uses Strand Displacement Amplification technology for the direct, qualitative detection of Chlamydia trachomatis DNA in clinician-collected female endocervical and male urethral swab specimens, patient-collected vaginal swab specimens (in a clinical setting), and male and female urine specimens. The assay is also intended for use with gynecological specimens collected in BD SurePath™ Preservative Fluid or PreservCyt™ Solution using an aliquot that is removed prior to processing for either the BD SurePath or ThinPrep™ Pap test. The assay is indicated for use with asymptomatic and symptomatic individuals to aid in the diagnosis of chlamydial urogenital disease.

The World Health Organization estimates that 92 million new cases of infection due to Chlamydia trachomatis are diagnosed each year.¹ In the United States, chlamydia is the most commonly reported infectious disease with over 1,000,000 cases in 2006, and case rates three fold higher among women than men.² Case rates for chlamydia infection have increased over the past decade in large part due to the expansion of screening programs for asymptomatic individuals and the use of increasingly sensitive diagnostic tests. Seventy to 90% of chlamydia infections in women are asymptomatic, with the result that long-term health problems can develop before a woman even knows she is at risk.³ C. trachomatis can cause long-term sequelae such as pelvic inflammatory disease and infertility, in addition to the birth of underweight babies. Fifty percent of C. trachomatis-infected men are also asymptomatic and, in the absence of treatment, infection can result in acute urethritis or epididymitis and chronic proctitis. Transmission of C. trachomatis occurs through sexual contact but can also take place in the birth canal leading to neonatal conjunctivitis and/or chlamydial pneumonia.⁴

Effective antibiotic treatment exists for chlamydial infections and the Advisory Committee on Human Immunodeficiency Virus (HIV) and Sexually Transmitted Disease (STD) Prevention encourages active control programs that target treatable STDs as a primary intervention in the HIV epidemic.⁵ In order to prevent complications and reduce transmission, the US Preventive Services Task Force has also published recommendations for screening young, sexually active women and those who are older and considered at increased risk of infection.^3,6

The Chlamydiaceae are gram-negative, obligate intracellular bacteria that form characteristic intracellular inclusions which can be observed in cell culture by fluorescence microscopy after antigen-specific staining is applied.⁷ Fifteen serovars of C. trachomatis are recognized comprising three groups, each of which is associated with a different disease state: the trachoma serovars, A-C; the occulogenital serovars D-K; and the Lymphogranuloma venereum serovars, L₁ – L₃. Current methods for diagnosis of C. trachomatis infection include culture and immunological assays, as well as the detection of nucleic acids by direct hybridization or amplification. Although historically culture has been the "gold standard" for detection of C. trachomatis, the enhanced sensitivity of amplified methods has led to their increasing adoption and in turn contributed to the rise in the number of reported cases of infection.

When used with the BD Viper System, the BD ProbeTec CT Q^x Amplified DNA Assay involves automated ferric oxide-based extraction of DNA from clinical specimens using BD FOX™ Extraction technology with the chemical lysis of cells, followed by binding of DNA to para-magnetic particles, washing of the bound nucleic acid and elution in an amplification-compatible buffer. When present, C. trachomatis DNA is then detected by Strand Displacement Amplification (SDA) of a specific target sequence in the presence of a fluorescently-labeled detector probe.^8,9

Quality control must be performed in accordance with applicable local, state and/or federal regulations or accreditation requirements and your laboratory's standard Quality Control procedures. It is recommended that the user refer to pertinent CLSI guidance and CLIA regulations for appropriate Quality Control practices.

The Control Set for the BD ProbeTec CT/GC Q^x Amplified DNA Assays is provided separately. One Positive and one Negative Control must be included in each assay run and for each new reagent kit lot number. Controls must be positioned according to the BD Viper Instrument User's Manual. The CT/GC Q^x Positive Control will monitor for substantial reagent failure only. The CT/GC Q^x Negative Control monitors for reagent and/or environmental contamination. Additional controls may be tested according to guidelines or requirements of local, state, and/or federal regulations or accrediting organizations. Refer to CLSI C24-A3 for additional guidance on appropriate internal quality control testing practices.¹⁴ The Positive Control contains approximately 2400 copies per mL of pCTB4 and pGCint3 linearized plasmids.

The Extraction Control (EC) oligonucleotide is used to confirm the validity of the extraction process. The EC is dried in the Extraction Tubes and is re-hydrated by the BD Viper System upon addition of the specimen and extraction reagents. At the end of the extraction process, the EC fluorescence is monitored by the instrument and an automated algorithm is applied to both the EC and C. trachomatis-specific signals to report specimen results as positive, negative, or EC failure.

Each BD ProbeTec CT Q^x Reagent Pack contains:

- CT Q^x Amplified DNA Assay Priming Microwells, 12 x 96: each Priming Microwell contains approximately 110 pmol oligonucleotides, 45 pmol fluorescently-labeled detector probe, 80 nmol dNTPs, with stabilizers and buffer components.

- CT Q^x Amplified DNA Assay Amplification Microwells, 12 x 96: each Amplification Microwell contains approximately 100 units DNA polymerase and 620 units restriction enzyme, with stabilizers and buffer components.

NOTE: Each microwell pouch contains one desiccant bag.

Control Set for the BD ProbeTec CT/GC Q^x Amplified DNA Assays: 24 CT/GC Q^x Positive Control Tubes containing approximately 2400 copies each of pCTB4 and pGCint3 linearized plasmids in carrier nucleic acid, and 24 CT/GC Q^x Negative Controls Tubes containing carrier nucleic acid alone. The concentrations of the pCTB4 and pGCint3 plasmids are determined by UV spectrophotometry.

Q^x Swab Diluent for the BD ProbeTec Q^x Amplified DNA Assays: 48 tubes each containing approximately 2 mL of potassium phosphate/potassium hydroxide buffer with DMSO and preservative.

Liquid-Based Cytology Specimen (LBC) Dilution Tube for the BD ProbeTec Q^x Amplified DNA Assays (LBC Specimen Dilution Tube): 400 tubes each containing approximately 1.7 mL of Tris/Sodium Chloride solution and preservative.

BD FOX Extraction Tubes: 48 strips of 8 tubes, each containing approximately 10 mg of iron oxide in a dissolvable film and approximately 240 pmol fluorescently-labeled Extraction Control oligonucleotide.

BD Viper Extraction Reagent and Lysis Trough: each 4-cavity Extraction Reagent trough contains approximately 16.5 mL Binding Acid, 117 mL Wash Buffer, 35 mL Elution Buffer, and 29 mL Neutralization Buffer with preservative; each Lysis Trough contains approximately 11.5 mL Lysis Reagent.

General:

1. For in vitro Diagnostic Use

2. Pathogenic microorganisms, including hepatitis viruses and Human Immunodeficiency Virus, may be present in clinical specimens. "Standard Precautions"^10-13 and institutional guidelines should be followed in handling all items contaminated with blood and other body fluids.

3. For additional specific warnings, cautions and notes specific to the BD Viper, consult the BD Viper System User's Manual.