| sandwich sign | <radiology> Ultrasound: hypoechoic solid mass, around central linear hyperechoic area, CT: soft-tissue density surrounding bowel, most likely to be lymphomatous involvement of mesentery (12 Dec 1998) |
|---|---|
| double antibody sandwich assay | For antigen; an application of the ELISA method in which material being tested for antigen is added to wells coated with known antibody; the presence of antigen fixed to the antibody coat can be determined either directly, by adding human antibody linked to the enzyme of the indicator system, or indirectly, by first adding unlabelled known antibody, the attachment of which to the antigen can be demonstrated by addition of immunoglobulin-specific antibody linked to the enzyme. (05 Mar 2000) |