#PICTURES OF VAGINA SHAPES HOW TO#
#PICTURES OF VAGINA SHAPES FULL#
#PICTURES OF VAGINA SHAPES SERIES#

Pseudopregnant outbred albino (CD-1) or hybrid agouti mice are often used as embryo recipients and detecting proestrus/estrus in these strains is straightforward. In the Jackson Laboratory's Reproductive Sciences group greater than 90% of mice “selected” as being in proestrus or estrus successfully mate overnight. Mice identified as being in proestrus or estrus are likely to be receptive to males making this method well suited for identifying mice likely to mate, facilitating timed mating. Additionally, with visual evaluation, there is no risk of inducing pseudopregnancy or damaging the vaginal epithelium as there may be with inserting a swab for collecting cells or a probe for measuring electrical conductance. Once a person is trained, approximately 100 females can be evaluated in 10–15 minutes, no extra equipment is required and evaluation can be completed without leaving the vivarium. The method for determining the stage of estrous by visual observation described by Champlin, et al is considerably quicker than the cytology or electrical impedance methods. One limitation, however, is that other estrous stages cannot be distinguished using this method. Alternatively, the electrical impedance of the vaginal epithelial cell layer during proestrus is higher than during other stages and can be measured using a probe to identify mice that are in proestrus. The vaginal cytology method is best used when all 4 stages of the estrous cycle need to be identified. Evaluating vaginal cells is accepted as the most accurate method for identifying all stages of the estrous cycle however, it is relatively labor intensive requiring vaginal cells to be collected, transferred to a glass slide, air dried, stained, and viewed. These changes can be detected using a variety of methods to determine the stage of estrous and include evaluating vaginal cytology, ,, , measuring electrical impedance, biochemical analysis of urine, and visual observation of the external genitalia. Ĭhanges occurring in the mouse estrous cycle are evident in the animal's physiology and anatomy.

#PICTURES OF VAGINA SHAPES FULL#

The cycle has been described in detail elsewhere and the reader is directed to these references for a full description. In the mouse, the estrous cycle is divided into 4 stages (proestrus, estrus, metestrus, and diestrus) and repeats every 4 to 5 days unless interrupted by pregnancy, pseudopregnancy, or anestrus. Identifying the stage of estrous is useful for choosing mice that will mate when paired with a male (to produce timed pregnancy or pseudopregnancy) or tracking the stage of estrous as a variable that may affect research.

#PICTURES OF VAGINA SHAPES HOW TO#

These images and descriptions are an excellent resource for learning how to determine the stage of the estrous cycle by visual observation or vaginal cytology. An identification tool is presented to aid the user in determining the stage of estrous when using vaginal cytology. When all 4 stages (proestrus, estrus, metestrus, and diestrus) need to be identified, vaginal cytology is regarded as the most accurate method.

#PICTURES OF VAGINA SHAPES SERIES#

Presented here are a series of images of the vaginal opening at each stage of the estrous cycle for 3 mouse strains of different coat colors: black (C57BL/6J), agouti (CByB6F1/J) and albino (BALB/cByJ).

Strain to strain differences, especially in coat color can make it difficult to determine the stage of the estrous cycle accurately by visual observation. Visual observation of the vagina is the quickest method, requires no special equipment, and is best used when only proestrus or estrus stages need to be identified. The efficiency of producing timed pregnant or pseudopregnant mice can be increased by identifying those in proestrus or estrus.

Pictures of vagina shapes