lal testing?
mat bernhardt
recollection it is a test used to detect the presence of endotoxin. a
detailed explantion of the test via e-mail would be greatly appreciated!
thanx!
--
fat elvis
C2F
you pay for love
but the hate comes free...
Dr. Stephen Dubin
test for endotoxin (AKA pyrogen) is/was to inject the material intravenously
in rabbits and look for temperature rise. Someone found some cells
in the lymph space of horseshoe crabs and made an extract which forms
a gel in the presence of endotoxin. There is now also a quantitative
form of the test using a colorimeter. One company that has kits with
the reagents (so you don't have to drill a hole in a crab) is Box
Whittaker Co in Maryland. They are very helpful and will send you
detailed instructions. You have to be very careful to use ultraclean
utensils and special pyrogen free water because common potable water
will usually give a positive test. Also watch out for vibration or
shaking if you are doing the gel form of the test. If you have any
trouble locating Box Whittaker, let me know and I will look on the
containers.
--
| Stephen Dubin VMD, PhD | |
| Biomedical Engineering & Science Institute | Phone: 215-895-2219 |
| Drexel University, Philadelphia PA 19104 | Fax: 215-895-4983 |
| email: dub...@duvm.ocs.drexel.edu | |
Bryan Kiehl
>i'm looking for what i believe is called 'lal testing.' to the best of my
>recollection it is a test used to detect the presence of endotoxin. a
>detailed explantion of the test via e-mail would be greatly appreciated!
>
sy...@microbiol.org
IM>i'm looking for what i believe is called 'lal testing.' to the best of my
IM>recollection it is a test used to detect the presence of endotoxin. a
IM>detailed explantion of the test via e-mail would be greatly appreciated!
IM>thanx!
IM>--
IM>fat elvis
IM>C2F
IM>you pay for love
IM>but the hate comes free...
Hi fat elvis,
Yes, there is such a thing that is widely used in the pharmaceutical
industry to test for the presence of bacterial endotoxins in parenteral
drugs. I would be happy to give you more information, but I thought you
were dead. Things must be very strange on the faculty of Wisconsin!
The test is based on the fortuitous finding that the horseshoe crab
(that's the Limulus part of Limulus Amoebocyte Lysate - LAL) produces a
blood factor that causes clotting when exposed to bacterial endotoxin
(that's the "AL" part). In practice, the test resembles serology tests,
were dilutions are prepared and a positive response (clotting) serves to
determine the range of deduced endotoxin concentrations.
This test has been studied and regulated to death. Search for Limulus,
bacterial endotoxin test, or parenteral manufacturing if your search
capabilities extend back to the 1950's and up. There may be something in
Medline (I haven't checked), but most info will be in books and reviews
at this point. Manufacturing and pharmaceutical references especially.
Good luck, let me know if I can help with any more info.
Scott Sutton
--
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Stephen Mamber
>
>The lal stands for Limulus Amebocyte Lysate. One company that has kits with
>the reagents is Box>Whittaker Co in Maryland.
That's BIO-Whittaker, 301-898-7025. Ask about their chromogenic LAL
assay, too. SWM
Dr Michael Kelsey
biological fluids, hence its use to detect endotoxin in pharmaceuticals, it
does not work well with biological fluids. Originally clotting was used to
detect endotoxin but was later replaced by a chromogenic factor Xa clotting
factor (memory may fail here). In CSF fluid it could detect down to nanaometer
quantities but serum was very dodgy.