Limits...
Optimization of electrically active magnetic nanoparticles as accurate and efficient microbial extraction tools.

Cloutier BC, Cloutier AK, Alocilja EC - Biosensors (Basel) (2015)

Bottom Line: EAMNP concentrations of 1.0 and 0.5 mg/mL provided optimal analytical sensitivity and analytical specificity.The entire IMS procedure requires only 35 min, and antibody-conjugated MNPs show no decline in performance up to 149 days after conjugation.This analytically sensitive and specific extraction protocol has excellent longevity and shows promise as an effective extraction for multiple electrochemical biosensor applications.

View Article: PubMed Central - PubMed

Affiliation: Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 275 Slappy Drive, Hamilton, GA 31811, USA. barbara.cloutier@us.army.mil.

ABSTRACT
Food defense requires the means to efficiently screen large volumes of food for microbial pathogens. Even rapid detection methods often require lengthy enrichment steps, making them impractical for this application. There is a great need for rapid, sensitive, specific, and inexpensive methods for extracting and concentrating microbial pathogens from food. In this study, an immuno-magnetic separation (IMS) methodology was developed for Escherichia coli O157:H7, using electrically active magnetic nanoparticles (EAMNPs). The analytical specificity of the IMS method was evaluated against Escherichia coli O55:H7 and Shigella boydii, and was improved over previous protocols by the addition of sodium chloride during the conjugation of antibodies onto MNPs. The analytical sensitivity of the IMS method was greatest when a high concentration of antibodies (1.0 mg/mL) was present during conjugation. EAMNP concentrations of 1.0 and 0.5 mg/mL provided optimal analytical sensitivity and analytical specificity. The entire IMS procedure requires only 35 min, and antibody-conjugated MNPs show no decline in performance up to 149 days after conjugation. This analytically sensitive and specific extraction protocol has excellent longevity and shows promise as an effective extraction for multiple electrochemical biosensor applications.

No MeSH data available.


Related in: MedlinePlus

Mean concentration (log10 of CFU/mL) of each bacterial culture captured in IMS, using Mab-EAMNPs made with 1.0 mg/mL antibody and with 0.5 mg/mL antibody. Statistical comparisons were made within numbered groups (1–3), and letters (a or b) indicate significant differences (α = 0.05, n =178, p = 0.018). Zero counts were estimated to facilitate analysis [23].
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4384083&req=5

biosensors-05-00069-f004: Mean concentration (log10 of CFU/mL) of each bacterial culture captured in IMS, using Mab-EAMNPs made with 1.0 mg/mL antibody and with 0.5 mg/mL antibody. Statistical comparisons were made within numbered groups (1–3), and letters (a or b) indicate significant differences (α = 0.05, n =178, p = 0.018). Zero counts were estimated to facilitate analysis [23].

Mentions: Two-tailed independent T-tests performed on the mean concentrations of captured cells (log10 of CFU/mL) for all three bacteria showed that the higher antibody concentration (1.0 mg/mL) caused a significant increase in capture of the target E. coli O157:H7 (n = 178; p = 0.018), with no significant effect on the capture of the negative control microorganisms. The higher antibody concentration (1.0 mg/mL) during conjugation increases the analytical sensitivity of EAMNPs at all Mab-EAMNP concentrations evaluated, and has no effect on analytical specificity (Figure 4).


Optimization of electrically active magnetic nanoparticles as accurate and efficient microbial extraction tools.

Cloutier BC, Cloutier AK, Alocilja EC - Biosensors (Basel) (2015)

Mean concentration (log10 of CFU/mL) of each bacterial culture captured in IMS, using Mab-EAMNPs made with 1.0 mg/mL antibody and with 0.5 mg/mL antibody. Statistical comparisons were made within numbered groups (1–3), and letters (a or b) indicate significant differences (α = 0.05, n =178, p = 0.018). Zero counts were estimated to facilitate analysis [23].
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4384083&req=5

biosensors-05-00069-f004: Mean concentration (log10 of CFU/mL) of each bacterial culture captured in IMS, using Mab-EAMNPs made with 1.0 mg/mL antibody and with 0.5 mg/mL antibody. Statistical comparisons were made within numbered groups (1–3), and letters (a or b) indicate significant differences (α = 0.05, n =178, p = 0.018). Zero counts were estimated to facilitate analysis [23].
Mentions: Two-tailed independent T-tests performed on the mean concentrations of captured cells (log10 of CFU/mL) for all three bacteria showed that the higher antibody concentration (1.0 mg/mL) caused a significant increase in capture of the target E. coli O157:H7 (n = 178; p = 0.018), with no significant effect on the capture of the negative control microorganisms. The higher antibody concentration (1.0 mg/mL) during conjugation increases the analytical sensitivity of EAMNPs at all Mab-EAMNP concentrations evaluated, and has no effect on analytical specificity (Figure 4).

Bottom Line: EAMNP concentrations of 1.0 and 0.5 mg/mL provided optimal analytical sensitivity and analytical specificity.The entire IMS procedure requires only 35 min, and antibody-conjugated MNPs show no decline in performance up to 149 days after conjugation.This analytically sensitive and specific extraction protocol has excellent longevity and shows promise as an effective extraction for multiple electrochemical biosensor applications.

View Article: PubMed Central - PubMed

Affiliation: Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 275 Slappy Drive, Hamilton, GA 31811, USA. barbara.cloutier@us.army.mil.

ABSTRACT
Food defense requires the means to efficiently screen large volumes of food for microbial pathogens. Even rapid detection methods often require lengthy enrichment steps, making them impractical for this application. There is a great need for rapid, sensitive, specific, and inexpensive methods for extracting and concentrating microbial pathogens from food. In this study, an immuno-magnetic separation (IMS) methodology was developed for Escherichia coli O157:H7, using electrically active magnetic nanoparticles (EAMNPs). The analytical specificity of the IMS method was evaluated against Escherichia coli O55:H7 and Shigella boydii, and was improved over previous protocols by the addition of sodium chloride during the conjugation of antibodies onto MNPs. The analytical sensitivity of the IMS method was greatest when a high concentration of antibodies (1.0 mg/mL) was present during conjugation. EAMNP concentrations of 1.0 and 0.5 mg/mL provided optimal analytical sensitivity and analytical specificity. The entire IMS procedure requires only 35 min, and antibody-conjugated MNPs show no decline in performance up to 149 days after conjugation. This analytically sensitive and specific extraction protocol has excellent longevity and shows promise as an effective extraction for multiple electrochemical biosensor applications.

No MeSH data available.


Related in: MedlinePlus