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Table 1 Parameters of the liposome detection reagent a)

From: Immunoliposome-PCR: a generic ultrasensitive quantitative antigen detection system

Parameter Value
Hydrodynamic diameter b) 117 ± 20 nm
Exposed biotin/lipid molar ratio c) 5.1 ± 0.2 mmol/mol
Reporter DNA/lipid molar ratio d) 2.1 ± 0.4 mmol/mol
CV of liposome reagent reproducibility e) 6 %
Liposome reagent stability f) 1.5 years at 4 °C
  1. a) The parameters were determined using measurements from 4 replicate preparations of the liposome detection reagent.
  2. b) The hydrodynamic diameter of the liposomes was determined by dynamic light scattering using a number-weighted Gaussian size distribution.
  3. c) The average number of biotin molecules exposed on the surface of the liposomes was estimated using a 4'-hydroxyazobenzene-2-carboxylic acid-avidin displacement quantification assay and the total lipid concentration. The total lipid concentration was determined from the absorbance of DHPE-rhodamine.
  4. d) The ratio of reporter DNA to total lipid, where the reporter concentration was measured by its absorbance at 260 nm.
  5. e) The CV for the reproducibility of the liposome detection reagent preparation was determined from the four replicate preparations by measuring the Ct value associated with equal concentrations of total lipid.
  6. f) The liposome detection reagent stability was defined as the length of time the liposomes could be stored at 4°C without observing a reduction in either the LOD or dynamic range when performing the CEA assay. See Table 2 for the LOD and dynamic range of the ILPCR assay for CEA in human serum.