Interaction of amphiphilic lipoarabinomannan with host carrier lipoproteins in tuberculosis patients: Implications for blood-based diagnostics
Fig 2
Assay optimization for the detection of LAM in human serum by lipoprotein capture assay.
Measurement of LAM by lipoprotein capture assay, as a function of concentration. (a) Representative spectral measurement of LAM (1.5 μM) incubated overnight at 4 °C in control human serum, with the specific signal (relative fluorescence units, RFU) from the detection of α-LAM antibody (15 nM) as a function of emission wavelength (nm). The background and non-specific signals are measured before the addition of LAM. (b) Lipoprotein capture assay was performed for the detection of LAM spiked into control serum at various concentrations and incubated overnight to allow incorporation of the amphiphile into carrier assemblies. Results are plotted as RFU as measured on the waveguide-based optical biosensor, at increasing concentrations of LAM. All values given in (b) are the mean ± standard deviation derived from at least two independent determinations (n = 2). Statistical significance was determined by Welch’s t-test using GraphPad Prism 8.