We introduce standard answers to frequently asked questions from customers on a daily basis on Q & A format.
For the samples whose endotoxin standard values are not determined under each Article of Pharmacopoeia, please set as follows.
Endotoxin limit(EU/mL) = K value (EU/kg)/Human maximum total dose administered (mL/kg) * 1
*1: When injections are administered frequently or continuously, they should be the maximum amount to be administered within one hour.
[ Reference ]
K value defined in Japanese, the US and European Pharmacopoeia (threshold pyrogenic dose of endotoxin)
|Intended Route of administration||K value (EU/kg)|
|Intravenous for radiopharmaceuticals||2.5|
Please apply to the following calculation formula, then confirm.
λ: ※ Labeled Gelation sensitivity by Gel-clot technique and the minimum concentration of standard curve by photometric method
Our Toxinometer and Toximaster QC which is the software attached to MPR Endotoxin Measurement System have the function to calculate MVD automatically.
Even water-insoluble sample, if it is soluble in 1% ethanol or 1% DMSO, it can be measured without affecting the lysate reagent.
If the sample is insoluble in the above solvent, by using 299-54501 Limulus PS Single Test Wako, it may be possible to measure without being effected by coexisting substances.
Ethanol, silicone oil, soybean oil, olive oil, stearic acid, egg yolk lecithin, oil adjuvant vaccine, albumin preparation, coagulation factor preparation (factor 8), interferon preparation, antithrombin III preparation, immunoglobulin preparation,etc, if they are soluble in ethanol can be measured.
Please check the following matters and preserve them.
If the pH of sample solution is not in the rang of 6.0 to 8.0, pH adjustment is necessary.
(The optimum pH of Bacterial Endotoxin test is around 7.3, but because the buffer component is contained in Lysate reagent in advance, it can be measured within pH6.0 - 8.0.)
If the sample can be diluted, the pH is adjusted by dilution. For samples that can not be diluted, pH adjustment is done by adding a dilution solution of NaOH or HCl to the sample solution.
Alternatively, it is possible to dilute the sample solution with a buffer solution. For pH adjustment, please use NaOH and HCl which are prepared beforehand.
Please refer to the following.
Normally, in a Lysate reagent, the reaction against (1 → 3)-β-D-Glucan of a cell wall constituent component of fungus also occurs in addition to endotoxin. Reagents prepared to react only with endotoxin are called Endotoxin-specific Reagents.
All Lysate reagents should be stored under refrigeration.
However, please save the dissolved Lysate reagent under the condition set for each reagent. When using it later, please cryopreserve it at the storage temperature
※ set for each Lysate reagent and use it within 2 weeks. Please do not repeat freezing and thawing more than one time.