Agarose gel electrophoresis of urease gene PCR. 20 μL of amplified products for the urease gene were electrophoresed on 0.8% agarose gel in TAE buffer (40 mM tris-acetate, 1 mM EDTA, pH 8). A) Lanes 1–14: PCR results of TA samples of newborns with RDS; lanes 15–16: U. urealyticum and U. parvum PCR positive control; lanes 17 and 24: 100 bp ladder; lanes 18–23 PCR results of TA or NF samples of newborns without RDS. B: PCR negativity for Ureaplasma spp. of respiratory secretions from the control group; lane 13: 100 bp ladder; lanes 19–20: U. urealyticum and U. parvum PCR positive control.