High Content Assays

High content cellular assays can offer more physiologically relevant assay results compared to biochemical assays. Broader adoption of cellular assays has been hindered in part by costly reagents and limited availability of cells. This issue has been especially acute for assays requiring primary or stem cells. It is further exacerbated when multi-step staining procedures require large amounts of labeled antibody.

DropArray ensures that cells are retained throughout all assay procedures and wash steps. Each assay in a 384-well DropArray microplate uses only 100 – 2,000 cells per data point, compared to the 3,000 – 10,000 cells per data point needed for conventional microplates. For a typical siRNA screen using an immuno-assay readout, the reduced sample and reagent volumes of the DropArray platform provide at least a 75% cost-savings.

Reagents and consumables Costs for a conventional
microtiter plate (25µL/well)
Costs for the DropArray 384
well plate (2µL/well)
Transfection reagent (eg. HiPerfect) $ 10,750 $ 1,075
Plate cost (for 160 plates) $ 824 $ 4,320
Commercial primary antibody for whole screen $12,900 $ 1,290
Total $ 24,474 $ 6,685

Cost savings of approximatlely 76% achieved on DropArray 384 over traditional 384 well micropaltes for a siRNA genome wide screen. Data courtesy IMCB.

To further facilitate high content assays, DropArray microplates provide the surface and optical properties needed for growing and imaging cells, even for assays requiring high (40x) magnification. The cyclic olefin copolymer (COC) used in DropArray microplates provides almost the same high-quality imaging that glass does, allowing even sub-cellular structural changes to be imaged. The flat surface of the DropArray microplate and the lack of meniscus effects offer superior optical properties than traditional microplates.

A. Control
Control

B. Blebbistatin
Blebbistatin

C. Cytochalasin D
Cytochalasin D

COS7 cells were treated with 50µM -(-)Blebbistatin, control medium or 0.4µM Cyto. D overnight. The cells were then fixed with 4% PFA and stained with phalloidin-FITC (green) to visualize the actin cytoskeleton and Hoechst (blue) for nuclei. Both Blebbistatin and Cyto. D caused drastic changes to the actin cytoskeleton as was expected. Scale bar = 70µm, 40X Images shown. Images courtesy of Genentech.

DMSO

Hela Cells

33 nM Wortmanin

Hela Cells

40× Images of Hela cells (control) and Wortmanin treated cells. GFP-LC3 (green); ToPro-3 dye nucleus stain (red).