Rat Vaginal Impedance Checker

  • The best method to know proestrus stage
  • Powerful tool for the improvement of reproduction efficiency
  • Simple operation
  • Battery-operated

MK-12 Rat Vaginal Impedance Checker has been designed to obtain a precise information on optimum day for mating during estrous cycle in the rats.

The electrical impedance of the epithelial cell layer of vaginal mucosa is measured at the frequency of 1 kHz by insertion of the probe into vagina. In the proestrus stage significantly high impedance is produced compared to that in the other stages of the estrous cycle. 3 kohm of impedance can be considered a standard indicating proestrus stage. Measuring range is 0 – 19.9kohm.

The conventional method known as vaginal smear method takes troublesome procedures such as taking smear, drying, dying and check-up using microscope. It really takes skill as well as time and labor.

Rat Vaginal Impedance Checker is a time & labor saving device on top of high reliability. Further, operation is so simple that even inexperienced personnel can easily use it.

NOTE: This product has been developed in cooperation with Chugai Pharmaceutical Co., Ltd.

mk11F1P: Proestrus

mk11F2∆: Changes of EIV during estrus cycle in the rats. EIV shows high value at proestrus stage and periodical alteration concurrently with estrus cycle

M. Koto (1987), Exp. Anim., 36(2), 195-198


The continuous use of the MK-12 Rat Vaginal Impedance Checker does not affect pregnancy rate or other reproduction achievements.


  • Bartos, L.(1975). Physiol. Bohemoslov., 24,427.
  • Bartos, L.(1977). Lab. Anim., 11,53-55
  • Bartos, L.(1977). Lab. Anim., 11,57-58
  • M..Koto(1987). Exp. Anim., 36(2),151-156.
  • M..Koto(1987). Exp. Anim., 36(2),195-198
  • Teradach,C.(1982). Sci. Tech. Anim. Lab.,7,49-84

The Standard System Includes:

  • MK-12 Main Unit – 1
  • RP-45A Rat Probe – 1
  • CA-100A Cable – 1
  • Rechargeable Battery (Ni-MH) – 4


Measurement Range0 - 19.9 Kohm
Accuracy(+)(-) 1 % (+)(-) 1 digit
Battery 2 Rechargeable Battery (Ni-MH)
Battery Life42 hours (When used continuously)
DimensionsW96 x D145 x H25 mm
WeightApprox. 180 g (Battery excluded)


RP-45A Rat Probe L55 x O.D.4.5 mm
MP-35 Mouse Probe L50 x O.D.3.5 mm

IMPORTANT NOTICE: The MK-12 has been developed exclusively for rats. A mouse probe is available upon request, but test results cannnot be guaranteed.


Specifications are subject to change without notice.