Physiology Core

Genetically modified mice are important tools for studying kidney physiology and diseases. However, expertise and equipment for physiological analysis of kidney function in mice are not readily available to many investigators in the renal research community. Furthermore, production of mutant mice has allowed investigators outside the renal community to uncover unexpected renal phenotypes and enter into renal research.

The objective of the Physiology Core is to help participating (established and new) renal investigators with a wide range of physiological techniques to study kidney physiology and diseases at the cellular, organ, and whole animal levels.

The Core will provide free services for certain assays; will provide advice, equipment, and training to assist center investigators’ laboratories to perform other assays; and will arrange collaborations with core directors on certain techniques that require extensive effort and advanced training.

IP-IB Klotho Assay

This assay is provided by the O'Brien Center as a service that incurs non-profit cost-recovery charges. In contrast to the commercial ELISA, we use an immunoprecipitation-immunoblot assay using synthetic anti-Klotho antibodies that reliably detects full-length Klotho in sera and urine from human, rat, and mouse.

Compared to the commercial assay, the drawback of our IP-IB assay is that it requires higher sample volume and cannot achieve high throughput mode, because of the laborious nature of the assay. However, the main advantage is the highly specific and sensitive reagents and known performance of inter-assay variation of 7 percent and intra-assay variation of < 2 percent.

Physiology Core Services

Request Services:

  • Measurement of serum and or urine Creatinine by Capillary Electrophoresis
  • Measurement of serum and urine citrate by capillary electrophoresis (in development)
  • Microanalysis of serum and urine electrolytes by: Flame photometry, Atomic absorption or Ion-Selective Electrode
  • Klotho IP-IB Assay

Schedule Equipment:

  • Blood-pressure measurement in mice and rats by tail-cuff method (training provided)
  • Measurement of serum and urine chemistry and blood gas (training provided)
  • Clearance studies in live animals by metabolic cages


  • Microdissection of tubules for quantitation of proteins/gene expression
  • Electrophysiological studies of ion channels by patch-clamp recordings
  • Microperfusion, dissection of individual tubules for real time PCR, western blot, and immunohistochemistry