carry-over

Also contains definition of: carry-over effect
https://doi.org/10.1351/goldbook.C00866
A process by which materials are carried into a reaction mixture to which they do not belong. These materials can be either parts of a specimen, or reagents including the diluent or wash solution. In such cases, carry-over means the transfer of material (specimen or reagents) from one container, or from one reaction mixture, to another one. It can be either unidirectional or bidirectional in a series of specimens or assays. The term carry-over effect is used for carry-over from specimen to specimen.
Sources:
PAC, 1989, 61, 1657. 'Nomenclature for automated and mechanised analysis (Recommendations 1989)' on page 1663 (https://doi.org/10.1351/pac198961091657)
PAC, 1991, 63, 301. 'Proposals for the description and measurement of carry-over effects in clinical chemistry (Recommendations 1991)' on page 302 (https://doi.org/10.1351/pac199163020301)