were first mentioned back in 1968 (1). In the 1970's the interest in luminescence was rapidly growing, both scientifically and commercially. This was driven by researchers looking for alternatives to radioactive isotopes and by new microbiological applications using the firefly/ATP reaction.
Other than homemade systems the only commercially available instrument at the time for this application was a Liquid Scintillation Counter (LSC). The LSC measured the luminescence by turning off one of the photomultiplier tubes and collecting the Counts per Second (CPS) for each sample. In the 1970's dedicated luminometers became commercially available and the very first dedicated luminometer was made by DuPont de Nemours in Wilmington DE (2). Applications were few in the early years and there were no practical methods for reagent handling, transport of samples, sample preparation and measurement of light yield. The use of firefly forwas sensitive but back in the 1970's the assay was still quite complex due to the firefly insects having to be collected by hand in the wild, freeze dried and then purified. This was an extremely lengthy process and could only be undertaken by experts.
On top of this, light detection sensitivity of the first dedicated luminometers which were using solid-state detectors, was still an issue. This lack-of-sensitivity issue was solved bydeveloping a new photon-counting method using selected high-performance photomultipliers. Based on the discrimination and identification of single photon events, this is still the most sensitive and stable method for light measurement in luminometry today. The result was the first commercially available luminometer from Berthold in 1977, the Biolumat LB 9500.
In the late 1970's new luminescence reagents were being developed at a rapid pace with higher stability and purity. Obviously, the next hurdle was to introduce these reagents into the sample with high precision and fast mixing capabilities. By 1979 Berthold was able to design the “Jet Injector” technology into the LB 9500 system. The introduction of these accurate and highly reproducible injectors enabled researchers to perform automatic standardizations and the comparison of results between different laboratories.
Berthold Technologies has engineered and developed over 20 different types of luminometers fromto in the past 4 decades. Renowned for precision, sensitivity and reliability Berthold Technologies is still the market leader for luminometers today.
(1) Burr A, Mauzerall D. The oxygen luminometer. An apparatus to determine small amounts of oxygen, and application to photosynthesis. Biochim Biophys Acta 1968; 153:614–24.
(2) Berthold F., Tarkkanen V. Luminometer development in the last four decades: recollections of two entrepreneurs. 2013 Jan-Feb;28(1):1-6