Glomerular Filtration Rate (FIT-GFR) Test

Technical Information

Drug safety has always played a key role in drug development. Unfortunately, drug toxicity studies often omit careful assessment of kidney function as indicated by recent publications.

Accurate measurements of kidney function using a measured glomerular filtration rate (GFR) test provides necessary and reliable information, while biomarker-based estimates are often misleading. On May 2010 (1), the FDA published a draft recommending that the drug development process should include a "measure" GFR.

Based on functional immunoassay technology (FIT™), BioPAL has developed immunoassay kits to measure the renal clearance of ideal filtration markers in order to obtain an accurate GFR measurement. We offer two different kits - Inulin (the gold standard) and Iohexol. Gadolinium-based kits have been discontinued (Gd-DTPA and Gd-DOTA).

(1) A recommendation from the conference is that in drug development, GFR should be measured directly with an inert tracer (e.g. inulin, iohexol, iothalamate, etc.) to determine pharmacokinetic or pharmacodynamic alterations due to kidney dysfunction. FDA KDIGO. Released draft. Guidance for Industry: Pharmacokinetics in Patients with Impaired Renal Function - Study Design, Data Analysis, and Impact on Dosing and Labeling. Docket Number FDA-2010-D-0133 May 16, 2010.


Measured GFR study compared to serum creatinine estimate

Due to the error associated with estimating GFR (eGFR) using biomarkers and correction equations, the above figure illustrates that researchers may miss important trends using eGFR that would otherwise be obvious using a direct measurement of kidney function (mGFR).

USP Inulin

BioPAL’s Inulin for Injection (USP) is for preclinical applications ONLY. However, BioPAL offers USP Inulin (I-1000) for researchers need to measure inulin clearance for human clinical research. Researchers may purchase USP Inulin (Solid) as a dry powder and then utilize a compounding pharmacy for formulation. BioPAL’s Inulin ELISA kits (FIT-0415) can then be used to measure its concentration is collected samples.

Kidney test to measure kidney function avoiding errors associated with serum creatinine.

Accurate kidney diagnostic that measures renal clearance in human research subjects.

Serum creatinine estimates of GFR (eGFR) are not accurate and are misleading.

The Product

BioPAL offers FIT-GFR™ (ELISA) kits that support either Inulin or Iohexol, as the filtration marker. Each kit is sold separately. Kidney function test to measure GFR. Iohexol clearance can be used in human research applications.

Iohexol is a clinically available CT contrast agent and is a known GFR marker. BioPAL’s FIT-GFR (Iohexol) kits are suitable for clinical research applications. Kidney function test to measure GFR.

Researchers can order FIT-GFR™ ELISA kits on-line. Two buffers that are required for performing the ELISA are also offered for on-line purchasing. Additional ELISA kit components are available and can be order by contacting BioPAL. A complete ELISA kit price list for each GFR marker is available below. Kidney function test to measure GFR.

Cat. No. Product Name Price (US) C of A MSDS  
FIT-0415 FIT-GFR™ Kit (INULIN) $600.00 GFR test Inulin
FIT-0515 FIT-GFR™ Kit (Iohexol) $600.00 GFR test Iohexol
FIT-0001 Standard and Sample Diluent $25.00 GFR test Gd-DTPA
FIT-0005 Wash Buffer Concentrate $30.00 GFR test Gd-DTPA
FIT-0408 Inulin for Injection (USP) 10 ml, 25 mg/ml $200.00
I-1000 Inulin USP (Dry Powder) 10 g $150.00

FIT-GFR Test Kit for Inulin

FIT-GFR Test Kit for Iohexol

GFR testGFR testGFR testGFR testGFR testGFR testMeasured glomerular filtration rate (mGFR, GFR) inulin
GFR testGFR testGFR testGFR testGFR testGFR testMeasured glomerular filtration rate (mGFR, GFR) iohexol

Serum creatinine provides a poor measurement of renal function. The best measurement of kidney function is a measured GFR study (mGFR) using either inulin or iohexol. GFR test!

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