Quantitation of Hsp70 in tissues using a competitive enzyme-linked immunosorbent assay

A competitive enzyme-linked immunosorbent assay has been developed to quantitate the Hsp70 levels in bovine tissues. Antibodies that show specificity to the low molecular weight form of Hsp70 (72 kDa) were developed in chickens, isolated from egg yolks, and characterized using Western blotting. Using this assay, we were able to verify quantitatively the previous observation that the low molecular weight form of Hsp70 exists at elevated levels in bovine skeletal muscle. Also, we report that the skeletal muscle contains the majority of the Hsp70 in the sarcoplasm, but a small amount of Hsp70 is localized in the sarcoplasmic reticulum. The amount of Hsp70 in bovine skeletal muscle is not a maximal level because it can be increased by heat stress. The reliability, specificity, and use of enzyme-linked antibodies instead of radioactive materials make this assay preferable over previous quantitation techniques.