Limits...
Photography by Cameras Integrated in Smartphones as a Tool for Analytical Chemistry Represented by an Butyrylcholinesterase Activity Assay.

Pohanka M - Sensors (Basel) (2015)

Bottom Line: A RGB color model was analyzed and color values for the individual color channels were determined.The assay was verified using plasma samples and samples containing pure BChE, and validated using Ellmans's assay.It can be concluded that the assay is expected to be of practical applicability because of the results' relevance.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Military Health Sciences, University of Defense, Trebesska 1575, Hradec Kralove CZ-50001, Czech Republic. miroslav.pohanka@unob.cz.

ABSTRACT
Smartphones are popular devices frequently equipped with sensitive sensors and great computational ability. Despite the widespread availability of smartphones, practical uses in analytical chemistry are limited, though some papers have proposed promising applications. In the present paper, a smartphone is used as a tool for the determination of cholinesterasemia i.e., the determination of a biochemical marker butyrylcholinesterase (BChE). The work should demonstrate suitability of a smartphone-integrated camera for analytical purposes. Paper strips soaked with indoxylacetate were used for the determination of BChE activity, while the standard Ellman's assay was used as a reference measurement. In the smartphone-based assay, BChE converted indoxylacetate to indigo blue and coloration was photographed using the phone's integrated camera. A RGB color model was analyzed and color values for the individual color channels were determined. The assay was verified using plasma samples and samples containing pure BChE, and validated using Ellmans's assay. The smartphone assay was proved to be reliable and applicable for routine diagnoses where BChE serves as a marker (liver function tests; some poisonings, etc.). It can be concluded that the assay is expected to be of practical applicability because of the results' relevance.

No MeSH data available.


Related in: MedlinePlus

Calibration of the smartphone-based assay using diluted plasma samples. Differences of color intensity for the R, G and B channels are given. These were acquired by processing photographs taken at the beginning (0 min) of the assay and after 30 min. Points in brackets was taken by assay of pure PBS. Error bars indicate standard deviations for n = 5.
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sensors-15-13752-f004: Calibration of the smartphone-based assay using diluted plasma samples. Differences of color intensity for the R, G and B channels are given. These were acquired by processing photographs taken at the beginning (0 min) of the assay and after 30 min. Points in brackets was taken by assay of pure PBS. Error bars indicate standard deviations for n = 5.

Mentions: A quite intensive coloration is visible for undiluted plasma (activity 2.73 × 10−5 kat/mL) and plasma diluted two, four as well as eight times (activity 1.37 × 10−5, 6.83 × 10−6 and 3.41 × 10−6 kat/mL) also had perceptible coloration. Full calibration is shown in Figure 4. The limits of detection were not equal when the three color channels were compared. The lowest limit of detection—3.09 × 10−6 kat/mL—was achieved for the R channel. Analysis of the G and B channels provided worse limits of detection than analysis of the R channel, as limits of detection of 4.36 × 10−6 kat/mL for the G channel and 4.67 × 10−6 kat/mL for the B channel were found, that is, the limit of detection was approximately two to four times lower (depending on the right source) compared to visual detection. From this point of view, the camera-based assay is better than the assay by naked eye. On the other hand, the limit of detection is not the only advantage when the two approaches are considered. The camera-based assay has good repeatability and allows easy reproducibility, while subjective reading by the naked eye has significant disadvantages regarding the repeatability and reproductibility.


Photography by Cameras Integrated in Smartphones as a Tool for Analytical Chemistry Represented by an Butyrylcholinesterase Activity Assay.

Pohanka M - Sensors (Basel) (2015)

Calibration of the smartphone-based assay using diluted plasma samples. Differences of color intensity for the R, G and B channels are given. These were acquired by processing photographs taken at the beginning (0 min) of the assay and after 30 min. Points in brackets was taken by assay of pure PBS. Error bars indicate standard deviations for n = 5.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507694&req=5

sensors-15-13752-f004: Calibration of the smartphone-based assay using diluted plasma samples. Differences of color intensity for the R, G and B channels are given. These were acquired by processing photographs taken at the beginning (0 min) of the assay and after 30 min. Points in brackets was taken by assay of pure PBS. Error bars indicate standard deviations for n = 5.
Mentions: A quite intensive coloration is visible for undiluted plasma (activity 2.73 × 10−5 kat/mL) and plasma diluted two, four as well as eight times (activity 1.37 × 10−5, 6.83 × 10−6 and 3.41 × 10−6 kat/mL) also had perceptible coloration. Full calibration is shown in Figure 4. The limits of detection were not equal when the three color channels were compared. The lowest limit of detection—3.09 × 10−6 kat/mL—was achieved for the R channel. Analysis of the G and B channels provided worse limits of detection than analysis of the R channel, as limits of detection of 4.36 × 10−6 kat/mL for the G channel and 4.67 × 10−6 kat/mL for the B channel were found, that is, the limit of detection was approximately two to four times lower (depending on the right source) compared to visual detection. From this point of view, the camera-based assay is better than the assay by naked eye. On the other hand, the limit of detection is not the only advantage when the two approaches are considered. The camera-based assay has good repeatability and allows easy reproducibility, while subjective reading by the naked eye has significant disadvantages regarding the repeatability and reproductibility.

Bottom Line: A RGB color model was analyzed and color values for the individual color channels were determined.The assay was verified using plasma samples and samples containing pure BChE, and validated using Ellmans's assay.It can be concluded that the assay is expected to be of practical applicability because of the results' relevance.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Military Health Sciences, University of Defense, Trebesska 1575, Hradec Kralove CZ-50001, Czech Republic. miroslav.pohanka@unob.cz.

ABSTRACT
Smartphones are popular devices frequently equipped with sensitive sensors and great computational ability. Despite the widespread availability of smartphones, practical uses in analytical chemistry are limited, though some papers have proposed promising applications. In the present paper, a smartphone is used as a tool for the determination of cholinesterasemia i.e., the determination of a biochemical marker butyrylcholinesterase (BChE). The work should demonstrate suitability of a smartphone-integrated camera for analytical purposes. Paper strips soaked with indoxylacetate were used for the determination of BChE activity, while the standard Ellman's assay was used as a reference measurement. In the smartphone-based assay, BChE converted indoxylacetate to indigo blue and coloration was photographed using the phone's integrated camera. A RGB color model was analyzed and color values for the individual color channels were determined. The assay was verified using plasma samples and samples containing pure BChE, and validated using Ellmans's assay. The smartphone assay was proved to be reliable and applicable for routine diagnoses where BChE serves as a marker (liver function tests; some poisonings, etc.). It can be concluded that the assay is expected to be of practical applicability because of the results' relevance.

No MeSH data available.


Related in: MedlinePlus