N Latex BTP Assay

Rapid Detection of CSF leakage and Easier Estimation of RRF

The N Latex BTP assay for use on Atellica® NEPH 630, BN™ II and BN ProSpec® Systems is a fast and accurate screening method for detection of cerebrospinal fluid (CSF) and estimation of residual renal function (RRF). A fully automated, random-access assay, the N Latex BTP assay employs a latex-enhanced, polyclonal reagent that provides high sensitivity, specificity, and lot-to-lot reproducibility.

  • Two applications—one accurate, convenient, fully automated assay.
  • Fast and accurate detection of CSF leakage.
  • Easy and reliable determination of RRF in dialysis patients.
  • High specificity and sensitivity for accurate results.
  • Low incidence of false-positive results.

Features & Benefits

Fast and Accurate Detection of CSF Leakage
The new N Latex BTP Assay is the first fully-automated method to provide accurate, rapid, and cost-effective determination of CSF leakage with a simple, nephelometric lab test. Testing can be performed on minimal sample volumes of human serum, heparinized and EDTA-plasma, and nasal or ear secretions containing CSF. Results are comparable to the β2-transferrin immunofixation electrophoresis method, but faster, easier, and less expensive.

  • High specificity of 100% and sensitivity of 99% for accurate results.1
  • Performance is not subject to CDT interference.
  • 12 minutes to result—time to result from sample collection to final result possible in 1 hour—less than half the time needed B2Trf, enabling faster surgical intervention.1,2
  • Low incidence of false-positive results helps reduce costly imaging testing and possible loss of life due to misdiagnosis.

Simple and Precise Monitoring of RRF
Beta-trace protein (BTP) measurement with the N Latex BTP assay offers simpler sample retrieval and increased accuracy of RRF determination when compared to other methods. It is the first assay to accurately, reliably and simply estimate RRF status with one serum sample.

  • Only a single serum sample is needed for determination of BTP
  • Allows estimation of renal contribution to clearance - without inaccurate and cumbersome urine collection
  • Supports decisions regarding dialysis modality selection
  • Provides information clinicians need to adjust dialysis regimen as well as to anticipate and manage complications.

Technical Specifications

Analytical Assay Performance

Assay principle
Latex-enhanced immunonephelometry

Sample type

human serum, heparinized and EDTA- plasma, urine, and CSF containing nasal or ear secretions

Measuring time

12 minutes

Reference range

CSF: 8.89 – 25.9 mg/L
Serum: ≤0.70 mg/L
Urine: ≤3.75 mg/L

Initial measuring range

0.22 – 14.0 mg/L

Once-opened reagent stability         

7 days (Atellica NEPH 630 and BN ProSpec® Systems)
3 days with evaporation stoppers on BN™ II System

Calibration frequency

4 weeks


Repeatability: < 6.1%
Within-lab: < 6.6%

Antigen excess security

up to 101 mg/L on BN ProSpec® System
up to 111 mg/L on BN™ II System