A Data Acquisition System for Automatic Grain Counting on Chromosome Autoradiographs
Abstract
The rate of synthesis of DNA during the progress of the mitotic cycle is different for chromosomes of different types. Its determination represents, therefore, a highly useful tool for choromosome analysis.
Controlled incorporation of H3 - labelled thymidin is commonly used to this purpose. Autoradioagraphs are then produced of the chromosome assembly at different stages of mitosis. The incorporated tritium shows up in the form of dark grains on these autoradiographs. The number of grains found in a particular chromosome is a measure of DNA synthesis up to this stage.
The present technique is to count these grains manually. This is a tedious and time consuming process. It was therefore decided to develop a system, which could perform this operation automatically and besides that determine certain dimensional parameters of the chromosomes to assist in the morphological classification.
The complete system can be divided into three parts: A data acquisition unit digitizes the optical information stored on photographic enlargements of the chromosome autoradiographs. A data preprocessing unit removes redundant information and stores the retained part on magnetic tape. The third part is the software for processing these data on a general purpose computer. Only the hardware part of the system has been completed so far and will be described in the paper in more detail.
