Compact, automatic set-up for ultra-weak photon emission measurements in organisms

Bertogna, Eduardo Giometti; Santos, Samuel Ricardo dos; Paterniani, José Euclides Stipp; Conforti, Evandro; Gallep, Cristiano M.

doi:10.1109/imoc.2011.6169247

Cited by 10 publications

(8 citation statements)

References 9 publications

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“…After acquiring basic knowledge of the daily rhythms present in UPE time profiles, a modified procedure was developed to better compare stressed and control samples: simultaneous experiments should be performed in similar setups (http://www.ft.unicamp.br/gallep/Gerais/setup.pdf) instead of sequential tests using the same equipment; the tested solution would not be added right at the beginning of the germination test but after 3 days of growth using distilled water and in the dark. With this approach the control and stressed samples exhibit UPE profiles that can be properly compared in time and in intensity, as demonstrated already for solutions (EC 50 and EC 100 ) of Hg and NaF .…”

Section: Recent Results: Lafa Datamentioning

confidence: 99%

Ultraweak, spontaneous photon emission in seedlings: toxicological and chronobiological applications

Gallep

2014

Luminescence

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The detection of ultraweak light emission in seedlings has been explored in toxicological and chronobiological studies. The main studies in this area are reviewed briefly, including a report on applied tests held in the last 7 years at LaFA--UNICAMP (Brazil). In general, results indicate that a linear relation for total light emission versus germination performance is found if only strong stress situations are considered, when external factors depress a seedling's development, even when considering a sequential series of tests. Light emitted by a single seedling was detected in a compact apparatus, and data are presented here for the first time showing pronounced circadian cycles are evident, with similar time and frequency profiles as those of the local gravimetric tide.

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Section: Recent Results: Lafa Datamentioning

confidence: 99%

Ultraweak, spontaneous photon emission in seedlings: toxicological and chronobiological applications

Gallep

2014

Luminescence

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“…Four series (sI, sII, sIII and sIV) were run using a home‐made apparatus [called PMT01, and described previously ], operating in photon‐counting mode with 10 4 acquisition points of 100 µs (counts per 100 µs). Briefly, the PMT01 photon‐count setup consists of a dark chamber connected to a photon‐count sensor based on a photomultiplier tube (H7360, Hamamatsu Photonics, Hamamatsu Photonics ‐ Hamamatsu City, Japan), a sample holder with temperature control, and an optical fiber ring connected to an external light source via an optical fiber + shutter, for controlled sample illumination.…”

Section: Methodsmentioning

confidence: 99%

“…Three more series (UV1, UV2 and UV3) were run using UV at 365 nm LED excitation for 30 s (275 lux) and photon counts per milliseconds (cpms). After external light excitation, the shutter was closed and, after a constant time delay of 0.3 s, photon‐counting started, the signals being transferred to a computer via a USB interface . All FD tests were repeated five times for each sample, as well as for the CFDA‐SE solution (background).…”

Section: Methodsmentioning

confidence: 99%

Fluorescence decay of dyed protozoa: differences between stressed and non‐stressed cysts

et al. 2015

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Several series of tests have shown that fresh, intact samples of Giardia duodenalis and Cryptosporidium parvum (oo)cysts are not marked by fluorescent probes such as carboxyfluorcein-succinimidyl-diacetate-ester (CFDA-SE), C12-resazurin and SYTOX® Green, probably because of their robust cell walls. These dyes fail to indicate the viability of such protozoa and allow negative responses to be recorded from living and infectious samples. Cryptosporidium parvum showed stronger isolation from chemicals, with living oocysts remaining unstained by the probe for up to 90 days after extraction. However, in further fluorescence decay (FD) experiments run with G. duodenalis samples stained using CFDA-SE (comprising living, non-stressed but aged cysts, heat-killed samples and UV-C-stressed samples) each showed a different FD decay profile, here studied in seven series of tests of five replicates each. The FD profiles were fitted by double-exponential decay kinetics, with the decay constant k2 being five times higher than k1. This FD procedure is fast and can be easily reproduced in 10 steps, taking ~ 1 h of laboratory work for already purified samples.

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“…The experimental setup for DL tests are shown at Figure 1; it is a dark chamber with photon-count module (photomultiplier tube + electronics) and fiber optic ring connect to external light source (halogen lamp) by fiber cable and electricalmechanical shutter, all automatic controlled by software; it includes also temperature control for samples using fluid flow (Bertonha, 2011).…”

Section: Methodsmentioning

confidence: 99%

Germination Vigour versus Delayed Luminescence of Coffee Seeds - Preliminary Series

Gallep

Amaral²,

Alonco³

et al. 2014

Proceedings of 2nd International Conference on Photonics, Optics and Laser Technology

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Nine coffee seeds samples submitted to different post-harvest treatments were tested in terms of ultra-weak delayed luminescence and induced to germinate afterwards. Hyperbolic decay function was used to quantify the time profiles and their fitting parameters were correlated to the correspondent germination vigour (total seedlings' elongation). Good linear relation was found (R 2 > 0.85) for the initial value parameter as well as for the decay velocity parameter. These preliminary results point to further tests in order to validate a photonic, non-invasive, non-destructive test for coffee seed's viability analyses.

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Compact, automatic set-up for ultra-weak photon emission measurements in organisms

Cited by 10 publications

References 9 publications

Ultraweak, spontaneous photon emission in seedlings: toxicological and chronobiological applications

Ultraweak, spontaneous photon emission in seedlings: toxicological and chronobiological applications

Fluorescence decay of dyed protozoa: differences between stressed and non‐stressed cysts

Germination Vigour versus Delayed Luminescence of Coffee Seeds - Preliminary Series

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