System for cell-based screening
The present invention provides systems, methods, screens, reagents and kits for optical system analysis of cells to rapidly determine the distribution, environment, or activity of fluorescently labeled reporter molecules in cells for the purpose of screening large numbers of compounds for those that specifically affect neurite outgrowth.
1. An automated method for analyzing neurite outgrowth comprising;
(a) providing an array of locations comprising cells, wherein the cells possess at least a first luminescently labeled reporter molecule that reports on cell location, and at least a second luminescently labeled reporter molecule that reports on neurite outgrowth, and wherein the cells comprise neurons;
(b) obtaining a nuclear image from the at least first luminescently labeled reporter molecule and a neurite image from the at least second luminescently labeled reporter molecule;
(c) automatically identifying cell bodies from the nuclear image;
(d) automatically identifying neurites extending from the cell bodies by identifying pixels in the neurite image that are not present in the nuclear image, wherein said pixels define neurites extending from the cell bodies; and
(e) automatically determining one or more features of the defined neurites.
2. The method of claim 1 further comprising contacting the neurons with a test compound and determining an effect of the test compound on neurite outgrowth.
3. The method of claim 2 , further comprising contacting the neurons with a neurotoxin either before, after, or simultaneously with the test compound.
4. The method of claim 1 wherein the first luminescently labeled reporter molecule comprises a DNA binding compound.
5. The method of claim 1 wherein the second luminescently labeled reporter molecule comprises a compound that selectively detects a cell component selected from the group consisting of cytoplasm, membrane, neuron-specific cell component, and cellular proteins.
6. The method of claim 2 , further comprising contacting the cells with a control compound known to stimulate neurite outgrowth, and determining an effect of the control compound on test compound-induced neurite outgrowth.
7. The method of claim 1 wherein the one or more features of the defined neurites comprise conditions that are toxic to neurons and affect neurite morphology.
8. The method of claim 1 wherein the second luminescently labeled reporter molecule is neuron-specific.
9. The method of claim 1 wherein the array of locations containing cells include cells other than neurons, and wherein the neurons possess a neuron-specific luminescent reporter molecule, and wherein the neuron-specific luminescent reporter molecule is spectrally distinguishable from the first and second luminescently labeled reporter molecule.
10. The method of claim 1 wherein identifying cell bodies comprises the steps of:
a. generating a kernel image from the nuclear image;
b. performing conditional dilations of the kernel image to identify cell bodies.
11. The method of claim 10 , wherein identifying neurites extending from cell bodies comprises the steps of:
a. generating a reservoir image from the neurite image; and
b. identifying positive pixels in the reservoir image that are not present in the cell bodies, wherein such positive pixels belong to neurites extending from cell bodies.
12. The method of claim 11 , further comprising
a. performing one conditional dilation of the kernel image to acquire a dilation image;
b. determining a set of nodes from the dilation image;
c. linking together connected nodes; and
d. repeating steps (a)-(c) until an entire neurite length has been traced.
13. The method of claim 1 , wherein sub-regions of the array of locations containing cells are sampled multiple times at intervals to provide kinetic measurement of changes in the distribution, environment or activity of the luminescent reporter molecules on or within the cells.
14. A computer readable storage medium comprising a program containing a set of instructions for causing a cell screening system to execute a method for analyzing neurite outgrowth, wherein the instructions comprise instructions causing the cell screening system to carry out procedures comprising
(a) imaging or scanning multiple cells in a plurality of locations on an array of locations comprising cells, wherein the cells possess at least a first luminescently labeled reporter molecule that reports on cell location, and at least a second luminescently labeled reporter molecule that reports on neurite outgrowth, and wherein the cells comprise neurons;
(b) obtaining a nuclear image from the at least first luminescently labeled reporter molecule and a neurite image from the at least second luminescently labeled reporter molecule;
(c) automatically identifying cell bodies from the nuclear image;
(d) automatically identifying neurites extending from the cell bodies by identifying pixels in the neurite image that are not present in the nuclear image, wherein said pixels define neurites extending from the cell bodies; and
(e) automatically determining one or more features of the defined neurites.
15. The method of claim 1 , wherein the one or more features of the defined neurites comprise one or more of the following:
a) Number of cells;
b) Number of neurons;
c) Total neurite length from all cells;
d) Total number of neurite branches from all cells;
e) Number of neurites per cell;
f) Number of neurites per positive neuron
g) Neurite length from each cell;
h) Neurite length per positive neuron
i) Neurite length per neurite
j) Number of cells that are positive for neurite outgrowth
k) Percentage of cells positive for neurite outgrowth;
l) cell body area;
m) number of branches per neuron;
n) number of branches per neurite; or
o) Degree of neurite outgrowth from a neuron or neuronal cell cluster.
16. The computer readable storage medium of claim 14 , wherein the instructions further comprise instructions causing the cell screening system to determine one or more features of the defined neurites selected from the group consisting of:
a) Number of cells;
b) Number of neurons;
c) Total neurite length from all cells;
d) Total number of neurite branches from all cells;
e) Number of neurites per cell;
f) Number of neurites per positive neuron
g) Neurite length from each cell;
h) Neurite length per positive neuron
i) Neurite length per neurite
j) Number of cells that are positive for neurite outgrowth
k) Percentage of cells positive for neurite outgrowth;
l) cell body area;
m) number of branches per neuron;
n) number of branches per neurite; or
o) Degree of neurite outgrowth from a neuron or neuronal cell cluster.