Liquid scintillation counting of 3H-thymidine incorporated into rat lens DNA.

DNA synthesis in the lens has previously been localized by autoradiography following incorporation of 3H-thymidine. For the quantification of DNA synthesis in the lens, pooling of lenses and extraction of the DNA for liquid scintillation counting, has formerly been adapted. In the present investigation a method has been developed for the extraction of the unincorporated tracer from whole lenses after short time incubation in a medium containing 3H-thymidine. The 3H-thymidine incorporated into individual lenses was then detected by liquid scintillation counting after dissolution of the lenses. The sources of the variation in the method are evaluated.