Immunophenotyping using gold or silver nanoparticle-polystyrene bead conjugates with multiple light scatter

Abstract

Background The type of antibody‐conjugated polystyrene (PS) latex beads for use as light scatter shift agents for targeted lymphocyte populations in whole blood has been expanded to include gold and silver nanoparticle‐aminodextran‐PS latex bead conjugates with antibodies. The linkers between antibody and colloidal metal were an aminotrithiol ligand or aminodextran polymer molecules. Methods A modified flow instrument, including forward light scatter (FS), side light scatter (SS), light scatter at other intermediate angle ranges, LMALS (10–20°) and UMALS (20–65°) was used for simultaneous bead probe measurements. A conventional flow cytometer was used in simultaneous bead‐fluorescent marker experiments. Results Two mutually exclusive cell populations, CD4+ and CD8+ lymphocytes, have been simultaneously enumerated in blood by using a mixture of CD4‐PS, CD8‐Au‐PS or CD4‐Au‐PS, CD8‐PS beads, and one laser line, 633 nm, excitation. Similar measurements were made with mixtures of CD4‐PS, CD8‐Ag‐PS or CD4‐Ag‐PS, CD8‐PS beads. Also, simultaneous use of bead and fluorescent markers mixed with whole blood was demonstrated with CD4‐PS beads and with the CD4‐RD1/CD8‐FITC dual marker. Conclusions Enumeration of CD4 and CD8 lymphocytes in whole blood by light scatter parameters only compared well with standard analyses with fluorescent markers. In simultaneous bead‐fluorescent marker labeling of lymphocytes, the labeled bead had to be mixed first with cells in whole blood. Cytometry 41:298–307, 2000. © 2000 Wiley‐Liss, Inc.

Detection of TiO2 nanoparticles in cells by flow cytometry

“…Both gold nanoparticles and Q-dots have been proposed to help view organelles within the cells (43,49). The unique properties of these small particles increase the signal-to-noise ratio of the staining reaction (42,43,(49)(50)(51)(52).…”

Cytotoxicity of β-D-glucose coated silver nanoparticles on human lymphocytes

“…There are some recent reports on the application of metallic NPs for diagnostic purposes, such as leukocytes immunophenotyping [27,28] but there is limited knowledge about the NPs haematological effects. In the experiments here reported, we used the so-called green chemistry for the synthesis of AgNPs-G, that allows to avoid any adverse effects of the conventional chemical synthesis.…”

“…In fact, use of NPs for immunophenotyping of lymphocytes has been recently reported [27,28] but there is still limited knowledge about the haematological effects of NPs.…”

Plasmonic flow cytometry by immunolabeled nanorods

“…We note that the bimodal resonance of nanorods also provides a smaller, blue-shifted secondary peak, which can be exploited for detection at an alternative wavelength. Second, these nanorods are not expected to significantly alter the general shape of the cell (19). Third, there is reduced scattering of 488 nm incident light for a nanorod of this size, minimizing changes in forward and side scattering at this wavelength, such that this labeling will not significantly interfere with complementary measurements of cell size and granularity by flow cytometry.…”

“…Further work demonstrated the use of gold and silver nanosphere-coated 2-lm polystyrene beads for immunophenotyping (19). This study seems to be the first that considered using an excitation source that matched the Mie theorypredicted surface plasmon resonance of the nanoparticles.…”