4 results about "Amoebocyte lysate" patented technology

Provided is a technology related to a horseshoe crab factor B variant, and also provided is means for performing endotoxin measurement with high sensitivity. A polypeptide having an amino acid sequence in which the amino acid residue at the 193-position in an amino acid sequence of a polypeptide of horseshoe crab factor B is substituted with a cysteine (Cys) residue, is produced. Endotoxin measurement can be carried out with high sensitivity by combining this polypeptide with horseshoe crab factor C, as a Limulus reagent.

This invention discloses a method for detecting bacterial endotoxins in gelatin microcarriers used for cell culture, comprising the following steps: (1) rechecking the sensitivity of the Limulus Amebocyte Lysate (LAL) reagent to ensure that the sensitivity result of the LAL reagent is between 0.5 and 2.0 λ; (2) determining the limit value and minimum dilution concentration of bacterial endotoxins in the gelatin microcarriers; (3) enzymatically digesting the PBS solution of the gelatin microcarriers to be tested with collagenase solution to obtain an enzymatic digest; (4) checking for bacterial endotoxins in the gelatin microcarriers: mixing a magnesium ion regulator and the LAL reagent to obtain a reconstituted LAL reagent, mixing the enzymatic digest obtained in step (3) with the reconstituted LAL reagent to obtain a mixed solution, and using the gelation method to determine whether bacterial endotoxins are present. By combining the pretreatment enzymatic digestion step with the LAL reagent reconstituted with a magnesium ion regulator, the gelatin microcarriers can be effectively enzymatically digested, fully releasing endotoxins, and the interference of phosphate ions can be effectively eliminated by the magnesium ion regulator, thereby improving the specificity and accuracy of the detection.

Resorbable implants, coverings and receptacles comprising poly(butylene succinate) and copolymers thereof have been developed. The implants are preferably sterilized, and contain less than 20 endotoxin units per device as determined by the limulus amebocyte lysate (LAL) assay, and are particularly suitable for use in procedures where prolonged strength retention is necessary, and can include one or more bioactive agents. The implants may be made from fibers and meshes of poly(butylene succinate) and copolymers thereof, or by 3d printing molding, pultrusion or other melt or solvent processing method. The implants, or the fibers preset therein, may be oriented. These coverings and receptacles may be used to hold, or partially / fully cover, devices such as pacemakers and neurostimulators. The coverings, receptacles and implants described herein, may be made from meshes, webs, lattices, non-wovens, films, fibers, foams, molded, pultruded, machined and 3D printed forms.

This invention discloses a gel detection method for bacterial endotoxins in high molecular weight biodegradable polyester materials, eliminating adsorption interference, belonging to the field of biomaterial safety testing technology. The method first uses dichloromethane to completely dissolve the polyester, disrupting its solid structure and releasing potentially adsorbed endotoxins. Then, liquid-liquid extraction is performed using water for bacterial endotoxin testing to transfer the endotoxins to the aqueous phase. Finally, a specific endotoxin dispersant is used to dilute the aqueous extract, effectively shielding the re-adsorption of free endotoxins by the hydrophobic groups of the polyester. The treated sample can be directly detected using the highly sensitive Limulus Amebocyte Lysate (LAL) gel electrophoresis method. This method is simple to operate, has good reproducibility, completely eliminates adsorption interference, and accurately and reliably controls the bacterial endotoxin limits of high molecular weight biodegradable polyester materials, ensuring their safety as medical materials.