type mtb h37rv  (ATCC)

Journal: BMC Infectious Diseases

Article Title: Non-continuous Percoll density gradient: a method for purifying Mycobacterium tuberculosis from dust

doi: 10.1186/s12879-025-12332-0

Figure Lengend Snippet: Schematic of the experimental workflow for method validation using H37Rv-spiked dust samples

Article Snippet: The MTB H37Rv reference strain (ATCC27294) was obtained from the American Type Culture Collection (ATCC, USA).

Techniques: Biomarker Discovery

Journal: BMC Infectious Diseases

Article Title: Non-continuous Percoll density gradient: a method for purifying Mycobacterium tuberculosis from dust

doi: 10.1186/s12879-025-12332-0

Figure Lengend Snippet: Determination of optimal Percoll density gradient for H37Rv separation from dust. ( A , D) Photographs of discontinuous ( A ) 5-layer and ( D ) 3-layer Percoll density gradients. Methylene blue was added to select layers during gradient preparation for visual clarity. The distinct interphases after centrifugation are formed by intrinsic density differences. Pure H37Rv (acid-fast stained, red bacilli) and unprocessed dust particles were layered. The pink background in the MTB sample tubes originates from the suspension medium of the stained bacilli; the actual localization of MTB is indicated by the turbid, cloudy bands at the density interfaces. ( B , E ) Quantitative comparison of H37Rv DNA recovery efficiency across gradient fractions, as determined by qPCR. Data are presented as mean ± SD ( n = 3). Statistical significance was analyzed by one-way ANOVA for multi-group comparisons and unpaired t-test for pairwise comparisons (*** p < 0.001, **** p < 0.0001). ( C ) Representative microscopic fields (1000× magnification) of acid-fast stained bacilli recovered from each layer of the 5-layer gradient (scale bar: 100 μm)

Article Snippet: The MTB H37Rv reference strain (ATCC27294) was obtained from the American Type Culture Collection (ATCC, USA).

Techniques: Centrifugation, Staining, Suspension, Comparison

Journal: BMC Infectious Diseases

Article Title: Non-continuous Percoll density gradient: a method for purifying Mycobacterium tuberculosis from dust

doi: 10.1186/s12879-025-12332-0

Figure Lengend Snippet: Viability assessment of H37Rv recovered via Percoll separation. ( A-E ) Macroscopic appearance of H37Rv colonies on LJ medium after 4 weeks of incubation. Left panels: Recovery standard controls (direct inoculation of pure H37Rv suspensions without dust). Right panels: Colonies recovered via Percoll separation from H37Rv-spiked dust samples. Initial spiking concentrations: ( A ) 10⁰, ( B ) 10¹, ( C ) 10², ( D ) 10³, ( E ) 10⁴ CFU/mL. ( F ) Quantitative comparison of viable MTB concentrations (CFU/mL) between Percoll-separated samples (from dust matrix) and direct inoculation controls (pure H37Rv). Colony counts were converted to CFU/mL for analysis. Bars represent mean ± SD ( n = 3). Statistical significance was determined by a paired t-test (ns, not significant; ** p < 0.01)

Article Snippet: The MTB H37Rv reference strain (ATCC27294) was obtained from the American Type Culture Collection (ATCC, USA).

Techniques: Incubation, Comparison

Journal: BMC Infectious Diseases

Article Title: Non-continuous Percoll density gradient: a method for purifying Mycobacterium tuberculosis from dust

doi: 10.1186/s12879-025-12332-0

Figure Lengend Snippet: Detection of MTB in air-conditioning dust from TB hospital wards using qPCR. ( A–D ) Representative qPCR amplification curves for MTB DNA detected in 25 clinical dust samples. Dashed lines: samples processed by Percoll separation. Solid lines: samples processed by direct DNA extraction. ( E ) qPCR amplification profiles for positive controls (H37Rv genomic DNA, red lines) and negative controls (no-template, green lines). ( F ) Examples of abnormal amplification curves obtained from the direct extraction method. ( G ) Violin plots comparing MTB DNA copy numbers between Percoll-based separation and direct extraction methods. Horizontal lines within violins represent the median and interquartile range. Statistical significance was determined by the Mann-Whitney U test (**** p < 0.0001)

Article Snippet: The MTB H37Rv reference strain (ATCC27294) was obtained from the American Type Culture Collection (ATCC, USA).

Techniques: Amplification, DNA Extraction, Extraction, MANN-WHITNEY