A trial for the improvement of the in vitro bioassay for human luteinizing hormones

In order to improve the sensitivity and the reliability of the in vitro bioassay for human luteinizing hormone, various strains of male mice at various chronological ages were sacrificed to obtained dispersed testes interstitial cell preparations. They consisted of DDN, DDY, DBA, C57, C3H, ICR, and BAL/C at 5, 7 and 9 weeks of age. The C57 Black strain, especially at 7 and 9 weeks of age, gave the most satisfactory standard dilution curve with a sensitivity of less than 12.5 microIU/tube, with a wide assayable range and with a parallelism to the sample dilution curve. Improvement of the assay is expected with the use of the C57 Black strain as the source of the cell suspension.