title: The gel test: some problems and solutions.
abstract: The gel centrifugation test (GT) is a method of transfusion serology, based on the fact that, after centrifugation, unagglutinated red blood cells (RBC) pass easily through a gel, while agglutinated RBC do not. The introduction of the GT to our blood bank transfusion routine [strictly following the manufacturer's instructions (DiaMed ID Micro Typing System)] resulted in problems with the interpretation of the results. These were overcome after the introduction of modifications, which included: (1) the systematic use of 1% RBC suspensions; (2) the use of 50 microliters of 1% RBC suspensions and 25 microliters of serum in all tests; (3) the control of all negative indirect antiglobulin tests (IAT) and direct antiglobulin tests (DAT) by the addition of 50 microliters of a 1% IgG coated RBC suspension followed by centrifugation; and (4) the systematic use of saline-suspended RBC for ABO typing in patients with positive DAT.
authors.affiliation: Service of Haematology, Hospital Geral de Santo António, Portugal.
authors.forename: M
authors.initials: M
authors.lastname: de Figueiredo
authors.forename: M
authors.initials: M
authors.lastname: Lima
authors.forename: S
authors.initials: S
authors.lastname: Morais
authors.forename: G
authors.initials: G
authors.lastname: Porto
authors.forename: B
authors.initials: B
authors.lastname: Justiça
mesh_terms: D001789:Blood Group Antigens; D001788:Blood Grouping and Crossmatching / Q000379:methods*; D002498:Centrifugation; D003298:Coombs Test; D005188:False Negative Reactions; D005189:False Positive Reactions; D005782:Gels; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D010641:Phenotype; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity
chemical_list: D001789:Blood Group Antigens; D005782:Gels; D007518:Isoantibodies; D011933:Reagent Kits, Diagnostic