Apparatus and method for closing a sample container

A method comprising:

• providing an applicator assembly that includes:
• a magazine configured to store a string comprising polymer-based material;
• an insertion device configured to insert an end piece of the string at least partly into an opening of the sample container;
• a drive system configured to supply at least a part of the string from the magazine to the insertion device and/or configured to drive at least a part of the insertion device to insert the end piece at least partly into the opening of the sample container;
• and
• a separator configured to separate the end piece from the string, such that the end piece forms a plug closing the sample container, wherein the separator is configured to rotate at least a part of the insertion device along a circumferential direction of the end piece to shear off the end piece from the string;
• and
• using the string to close the sample container.