A few questions about luminometer...

[Dr Engelbert Buxbaum]

kthsu2002 at yahoo.com wrote:


> 1. What is a luminometer?
> 2. How is luminometer different from a liquid scintillation counter?
> (Both instruments count photons?)

Yes, but the kinetics is different. in a beta-szintillation counter the
photons are produced over a fairly long time, half-life periode for
biologicaly important isotopes ranges from days (32P) to thousands of
years (14C). 

Chemoluminescence comes either as glow- or as flash-kinetics. Typical
example for glow kinetics is horseraddish peroxidase, the reaction lasts
for several minutes to half an hour. With some precautions regarding
standardisation one can count that in a szintillation counter, the use
of a luminometer is however more convenient.

Flash-kinetics you get with certain unstable compounds, and measuring
this requires a luminometer that can inject chemicals into the sample
and then immediately measure light output. The reaction is over within a
second or so.