Background Mucins and glycoproteins in the cervicovaginal environment are an important component of female genital tract (FGT) innate immunity. Optimally, microbicide use should not disrupt the mucus layer protecting the genital epithelium. The objective of this study was to characterise the glycoproteins and mucin components of cervical mucus to determine differences due to the menstrual cycle or method of contraceptive.

Methods Cervical mucus samples were collected from 120 normal healthy volunteers using a Catamenial cup placed over the cervix for 30 min. Aliquots were stored at –80^oC. The six groups (20 participants per group) were: healthy asymptomatic post-menopausal women (PM), women in the proliferative or follicular phase, and women using levonogerestrol IUDs, DMPA or combined oral contraceptives.

Proteins were separated by SDS-PAGE using both 12% Bis Tris and 3–8% Tris acetate acrylamide gels. The gels were stained with Coomassie blue (CM) for (12%gels) or silver stain for (3–8%). Albumin concentrations were measured using ELISA. Western blots were prepared in an iBlot system.

Results The albumin values were very similar between groups, avg. 0.72 ± 0.01 ng/ng protein. Mucins and other glycoproteins were visualised by silver stain, and appeared in the 300 Kdal area of 3–8% gels. These proteins were not resolved into a single band. CM staining and sorting of samples revealed 8 distinct protein banding patterns, PBP, (range 50–80 Kdal, 12% gel). Most PBPs were found in different groups, except Type I was only found in the PM group (50%). Western blots revealed most of these bands to be hydrolysis fragments of albumin.

Conclusion The women in all six study groups had similar quantities of albumin. Cervical mucus presents as 8 different protein banding patterns. At present, these data suggest the groups differ in how they metabolise albumin and by extension other protein in the cervical mucus.