Thixotropic gel is an inert (nonreacting) synthetic substance in the bottom of certain tubes. When a specimen in a gel tube is centrifuged the gel undergoes a change in viscosity and moves to a position between the cells and the serum or plasma, forming a physical barrier between them. This separation prevents the cells from continuing to metabolize substances such as glucose in the serum or plasma.
Placement of Citations. 1  Place a citation as close to the quoted or paraphrased material as possible without disrupting the sentence. 2  When material from one source and the same page numbers is used throughout a paragraph, use one citation at the end of the paragraph rather than a citation at the end of each sentence.
1. Choose the citation format you require and then click the resource you wish to cite from the left. 2. Fill out the form which will appear on right using the information from your source. 3. Click âMake citationâ button at the bottom of the form to generate citation.