To provide a method for producing a horseshoe crab recombinant Factor C. The horseshoe crab recombinant Factor C is produced through expression thereof by use of mammalian cells such as CHO DG44 and HEK293 as host cells.

To provide a method for producing a horseshoe crab recombinant Factor C. The horseshoe crab recombinant Factor C is produced through expression thereof by use of mammalian cells such as CHO DG44 and HEK293 as host cells.

An object of the present invention is to provide a method for enhancing a sensitivity of a current endotoxin measuring reagent employing a recombinant protein to the endotoxin of Helicobacter pylori. The present invention provides a method for enhancing the sensitivity of an endotoxin measuring reagent to the endotoxin of Helicobacter pylori, the endotoxin measuring reagent containing a recombinant protein of horseshoe crab factor C, the method including increasing a content of the recombinant protein of factor C at the time of endotoxin measurement to an amount that is sufficient for enhancing the sensitivity.

An object of the present invention is to provide a method for enhancing a sensitivity of a current endotoxin measuring reagent employing a recombinant protein to the endotoxin of Helicobacter pylori. The present invention provides a method for enhancing the sensitivity of an endotoxin measuring reagent to the endotoxin of Helicobacter pylori, the endotoxin measuring reagent containing a recombinant protein of horseshoe crab factor C, the method including increasing a content of the recombinant protein of factor C at the time of endotoxin measurement to an amount that is sufficient for enhancing the sensitivity.

A method of determining the result of an assay in a microfluidic device includes the steps of: dispensing a sample droplet onto a first portion of an electrode array of the microfluidic device; dispensing a reagent droplet onto a second portion of the electrode array of the microfluidic device; controlling actuation voltages applied to the electrode array to mix the sample droplet and the reagent droplet into a product droplet; sensing a dynamic property of the product droplet; and determining an assay of the sample droplet based on the sensed dynamic property. The dynamic property is a physical property of the product droplet that influences a transport property of the product droplet on the electrode array. Example dynamic properties of the product droplet include the moveable state, split-able state, and viscosity based on droplet properties. The method may be used to perform an amoebocyte lysate (LAL) assay.

The present invention addresses the problem of providing a means for making highly sensitive and stable measurements possible using electrochemical measurement methods. This problem is resolved by providing: a labeling substance represented by general formula (1) and used to label a substrate; a measurement substrate that is formed by being labeled using the labeling substance; a method of measuring using electrochemical measurement methods that use the measurement substrate; and a reagent kit that includes as components the labeling substance and/or the measurement substrate. ##STR00001##
(In general formula (1), R.sub.1 is either H or an alkyl group (C.sub.mH.sub.2m+1), m is an integer of 1-4, R.sub.2 is an alkyl group (C.sub.nH.sub.2n+1), and n is an integer of 1-4.)

The present invention addresses the problem of providing a means for making highly sensitive and stable measurements possible using electrochemical measurement methods. This problem is resolved by providing: a labeling substance represented by general formula (1) and used to label a substrate; a measurement substrate that is formed by being labeled using the labeling substance; a method of measuring using electrochemical measurement methods that use the measurement substrate; and a reagent kit that includes as components the labeling substance and/or the measurement substrate. ##STR00001##
(In general formula (1), R.sub.1 is either H or an alkyl group (C.sub.mH.sub.2m+1), m is an integer of 1-4, R.sub.2 is an alkyl group (C.sub.nH.sub.2n+1), and n is an integer of 1-4.)

It is necessary to establish a purification method effective for the removal of endotoxin, in order to obtain thermolysin containing a reduced amount of contaminant endotoxin. On the premise of the establishment, accurate measurement of the amount of endotoxin that contaminates thermolysin is required. The present invention addresses the problem of providing a novel measurement method which enables accurate measurement of the amount of endotoxin that contaminates thermolysin. The present invention also addresses the problem of providing thermolysin containing a reduced amount of contaminant thermolysin, and the use thereof. There is provided thermolysin containing contaminant endotoxin in an amount of 1 EU/mg or less. There is also provided a method for measuring endotoxin that contaminates thermolysin, the method including pretreatment of deactivating the thermolysin. An enzyme preparation including the thermolysin according to the present invention as an active ingredient has a high utility value in the field of regenerative medicine.

It is necessary to establish a purification method effective for the removal of endotoxin, in order to obtain thermolysin containing a reduced amount of contaminant endotoxin. On the premise of the establishment, accurate measurement of the amount of endotoxin that contaminates thermolysin is required. The present invention addresses the problem of providing a novel measurement method which enables accurate measurement of the amount of endotoxin that contaminates thermolysin. The present invention also addresses the problem of providing thermolysin containing a reduced amount of contaminant thermolysin, and the use thereof. There is provided thermolysin containing contaminant endotoxin in an amount of 1 EU/mg or less. There is also provided a method for measuring endotoxin that contaminates thermolysin, the method including pretreatment of deactivating the thermolysin. An enzyme preparation including the thermolysin according to the present invention as an active ingredient has a high utility value in the field of regenerative medicine.

The invention relates to a method for preparation of a sample (10) of a formulation (11) for subsequent endotoxin determination, the formulation (11) suspected of comprising an endotoxin, the formulation (11) preferentially being a pharmaceutical formulation. The method comprises the following steps: application of the sample (10) to an endotoxin-free centrifugation column (2) containing a size exclusion chromatography matrix (5) that has been equilibrated with a suitable equilibration buffer (6) and elution of a flow through (15) of the sample by centrifugation, which flow through (15) can then be used for endotoxin determination. The equilibration buffer (6) is selected according to a subsequently used method of endotoxin determination, the equilibration buffer (6) only containing components not interfering with subsequently used method of endotoxin determination. Furthermore, the invention relates to a kit (20) for preparation of a sample (10).