Indium-111 tropolone, a new high-affinity platelet label: preparation and evaluation of labeling parameters.
Platelets were isolated with a new neutral, lipid-soluble metal complex of indium-111 and tropolone. Unlike oxine, which must be dissolved in ethyl alcohol, tropolone is soluble saline. Platelet labeling with In-111 tropolone can be performed in both acid-citrate-dextrose (ACD)-plasma and ACD-saline media within two hours' time. Labeling efficiency has been 80-90% in ACD-saline and 60-70% in the ACD-plasma medium. Optimum concentrations for the labeling of platelets with In-111 tropolone were 5 micrograms/ml in ACD-saline and 10 micrograms/ml in ACD-plasma, using a 15-min incubation at room temperature. A kit formulation for convenient routine preparation of In-111-labeled platelets has been developed. Seven parameters of platelet labeling were studied: concentration of tropolone, citrate, plasma proteins, and calcium ions; also platelet density, temperature, and pH of incubation medium. Their effects on the mechanism of platelet labeling with lipid-soluble tracers are discussed.
D000345:Affinity Labels; D001792:Blood Platelets; D019343:Citric Acid; D003508:Cycloheptanes; D005947:Glucose / Q000031:analogs & derivatives; D006801:Humans; D007204:Indium; D007553:Isotope Labeling; D011868:Radioisotopes; D011933:Reagent Kits, Diagnostic; D014334:Tropolone
D000345:Affinity Labels; D003508:Cycloheptanes; D011868:Radioisotopes; D011933:Reagent Kits, Diagnostic; D007204:Indium; C002113:acid citrate dextrose; D019343:Citric Acid; D014334:Tropolone; D005947:Glucose