DNA sequence detection of nucleated red blood cells
Genetic modification or selection of avians requires that large numbers of birds be genetically analyzed for sequences of interest. Typically, DNA is extracted on an individual basis from samples taken from the birds. Current methods of DNA extraction extract the DNA from blood or other tissues using tedious and time-consuming procedures. The present invention provides a high throughput screening assay for detecting a genetic sequence in multiple samples. The assay further provides a DNA extraction method that allows DNA to be extracted rapidly from multiple avian samples, such as red blood cells. The extraction method is extremely reliable and does not require that each sample be quantitated post-extraction. The extracted DNA can be used for a variety of genetic assays, including a high throughput screening assay to identify insertion of a transgene. The present invention is particularly useful for extracting DNA from nucleated RBCs. Therefore, the method can be applied towards genetic analysis of avians, fish, reptiles and amphibians.
1 . A method for isolating nucleic acid from a chicken comprising:
obtaining a blood sample comprising nucleated blood cells from a bird;
adding to a container, the blood sample and a plasma membrane lysis buffer wherein the container binds a precipitated nucleic acid;
centrifuging the container to yield a supernatant and a pellet;
removing the supernatant from the container;
adding to the container a nucleic acid release lysis buffer;
incubating the container such that nucleic acid is released;
precipitating the nucleic acid samples in the container producing a supernatant;
removing the supernatant; and
dissolving the nucleic acid in a solvent, thereby isolating nucleic acid from a bird.
2 . The method of claim 1 wherein the container comprises polystyrene.
3 . The method of claim 1 wherein the biological sample comprises blood.
4 . The method of claim 1 wherein the plasma membrane lysis buffer comprises one or more components selected from the group consisting of sucrose, Tris buffer, MgCl 2 , Triton X-100 and protease.
5 . The method of claim 1 wherein the plasma membrane lysis buffer comprises one or more components selected from the group consisting of between about 0.05M and about 1.0M sucrose, between about 5mM and about 500 mM Tris—HCl at a pH between about 5.0 and about 9.0, between about 1 mM and about 50 mM MgCl 2 and between about 0.1% w/vol and about 10% w/vol Triton X-100 and protease.
6 . The method of claim 1 wherein the plasma membrane lysis buffer comprises between about 0.05M and about 1.0M sucrose, between about 5 mM and about 500 mM Tris—HCl at a pH between about 5.0 and about 9.0, between about 1 mM and about 50 mM MgCl 2 and between about 0.1% w/vol and about 10% w/vol Triton X-100.
7 . The method of claim 1 wherein the nucleic acid release lysis buffer comprises one or more components selected from the group consisting of Tris buffer, NaCl, EDTA and protease.
8 . The method of claim 1 wherein the nucleic acid release lysis buffer comprises one or more components selected from the group consisting of between about 5 mM and about 100 mM Tris-HCl at a pH between about 5.0 and about 9.0, between about 1 mM and about 100 mM NaCl, between about 1 mM and about 100 mM EDTA and protease.
9 . The method of claim 1 wherein the nucleic acid release lysis buffer comprises between about 5 mM and about 50 mM Tris-HCl at a pH between about 7.0 and about 9.0, between about 1 mM and about 50 mM NaCl, between about 1 mM and about 50 mM EDTA and protease.
10 . The method of claim 1 wherein the container is a compartmentalized container.
11 . The method of claim 1 wherein a multi-well plate comprises the container.
12 . The method of claim 1 wherein the nucleic acid precipitating solution comprises ethanol.
13 . The method of claim 1 comprising washing the precipitated nucleic acid.
14 . The method of claim 1 comprising drying the precipitated nucleic acid.
15 . The method of claim 1 wherein the period of time sufficient to release the nucleic acid is less than eight hours.