An evaluation of the performance of ten commercial luminometers

A novel method is described for the on-line determination of viable cell number. It has been tested in fermentations of Escherichia coli. The cells are transfected with the gene for firefly luciferase and fed low levels of luciferin in the medium. The reaction requires ATP, so the nonviable cells cannot produce light. Thus, light production is linear with viable cell density from innoculation through most of exponential growth. The light emitted by these cells is then conducted from the reaction vessel to the light detection equipment by an optical fiber. With the equipment described below, as few as a 10(6) cells/mL, or an OD(600) of 0.004, are easily detectable and concentrations greater than 10(10) cells/mL are well within range. The data are collected by a computer, so adaptation to on-line control applications is straightforward. During lag phase, this method is much more accurate then optical density measurements. At the end of exponential growth, rapid changes in light production mark carbon source depletion and the onset of cell lysis. A simple model accounts for the luciferin used during the fermentation and corrects the light detected to the proper cell density.

show abstract

“…If these parameters are used in Eq. (8) on fermentation data, light detection tracks cell density very nicely (see Fig. 7).…”

Section: Modelingmentioning

confidence: 82%

In situ fermentation monitoring with recombinant firefly luciferase

Lasko

Wang

1993

Biotech & Bioengineering

View full text Add to dashboard Cite

show abstract

“…The relative light unit (RLU), the instrument reading, was devised early on by Lumac as instruments varied in output sensitivity and as was seen later, between luminometers from other manufacturers. An inter‐instrument comparison made later in 1989 showed this wide variation .…”

Section: The 1970smentioning

confidence: 94%

Luminometer development in the last four decades: recollections of two entrepreneurs

Berthold¹,

Tarkkanen²

2012

Luminescence

View full text Add to dashboard Cite

This article, written by two entrepreneurs in luminescence, traces their involvement in the major part of the interconnected innovation and development of luminometers, adenosine triphosphate (ATP) bioluminescence and other technologies from the mid-1970s to 2011 that ushered in much of the field of luminometry as we know it today. Key developments leading to current commercial applications of ATP bioluminescence, luminescence immunoassay, cellular luminescence, reporter gene and other applications are described from the first tube luminometers derived from early luminescence studies using liquid scintillation counting technology to measuring bioluminescence from crude ATP and firefly tail extracts.

show abstract

“…The biofilm on the back of the last (third) RBC disc was sampled by removing the biofilm from a segment of about one‐twelveth of the disc surface using a sterilized blade, placing it in a universal tube containing 13 ml sterilized quarter‐strength Ringer’s solution, homogenizing for 10 s and dividing into three parts. The first part of the homogenized biofilm sample was analysed for ATP content using a luciferin–luciferase reagent (Celsis.Lumac, Landgraaf, The Netherlands) (Jago et al . 1989; Marriott et al .…”

Section: Methodsmentioning

confidence: 99%

A study of the effect of isothiazolones on the performance and characteristics of a laboratory-scale rotating biological contactor

2001

View full text Add to dashboard Cite

Aims:To study the effect of the isothiazolone biocide (Kathon WT) on the performance of laboratory-scale rotating biological contactors (RBCs) and their component bio®lms. Methods and Results: Bio®lms were established on the RBCs and then exposed to 0á7±15 p.p.m. isothiazolones. Young, 1-week-old, bio®lms were found to attain treatment ef®ciency equal to that of mature, 2-month-old, bio®lms. Isothiazolone concentrations at 3 p.p.m. and above caused a progressive decline in treatment ef®ciency and 15 p.p.m. isothiazolones inhibited all microbial activity and resulted in the death of the bio®lms. Biooxidation and the biodegradation of isothiazolones within the bio®lms continued unhindered at concentrations which caused the total inhibition of planktonic bacteria. Conclusions: There was at least a 10-fold difference in susceptibility of planktonic and bio®lm bacteria to isothiazolones. The chemical oxygen demand (COD) test was shown to be a reliable tool for investigating the ef®ciency of wastewater treatment units when the in¯uent contains isothiazolones, while the biochemical oxygen demand (BOD) 1 test was unreliable due to the inhibition of bio-oxidation by the biocide. Signi®cance and Impact of the Study: The results show that RBCs can be used to treat ef¯uents containing isothiazolones at concentrations up to 1á5 p.p.m.

show abstract

An evaluation of the performance of ten commercial luminometers

Cited by 30 publications

References 11 publications

In situ fermentation monitoring with recombinant firefly luciferase

In situ fermentation monitoring with recombinant firefly luciferase

Luminometer development in the last four decades: recollections of two entrepreneurs

A study of the effect of isothiazolones on the performance and characteristics of a laboratory-scale rotating biological contactor

Contact Info

Product

Resources

About