A simple DNA disc chip in a microarray design based on modified comparative genomic hybridization for sperm DNA analysis.

ABSTRACT

OBJECTIVE: A DNA disc chip assay, based on comparative genomic hybridization, was designed to measure changes in sperm DNA intensities. The objective was to analyze the DNA integrity of hyperactive sperm cells after mild heat treatment. DESIGN: The assay based on a multiple cell comet assay was used to analyze changes in genomic DNA. Washed sperm DNA were tested on the assay and images stored in a microarray design. SETTING: Clinical and academic research environment. PATIENT(S) Frozen-thawed washed sperm from different donors (n = 7). INTERVENTION(S) Discarded sperm leftover from trial washes carried out at 37 degrees and 40 degrees C were frozen and processed for the DNA disc chip assay. MAIN OUTCOME MEASURE(S) Fluorescent intensities of DNA disc chips and sperm variables. RESULT(S) Heat treatment resulted in more than eightfold increase in sperm hyperactive motility with little degradation in DNA integrity. Sperm with low hyperactivation was associated with alterations in DNA after heat treatment. CONCLUSION(S) The DNA disc chip assay was simple, inexpensive, and permitted assisted reproduction technologies laboratories to use comparative genomic hybridization for cytogenotoxicity testing. However, the assay required manual processing, a fluorescent microscope, and computer. The data showed an association between sperm hyperactivation and DNA integrity suggesting that the hyperactivation marker may be used for selecting quality sperm for intracytoplasmic sperm injection. More studies are needed to examine temperature effects on ejaculated human sperm.