there is a possibility

of occurrence of false positives

Heterophile antibodies may be found in disease other than Infectious Mononucleosis.

Low titers have been detected in cytomegalic inclusion disease and Toxoplasmosis

5. Incorrect interpretation of results Ensure that the results are interpreted at 3 minute and as per instructions given in the

package insert. Positive and negative controls should be run with each series of tests

and results should be compared with these

Possible causes Solutions

1. Prozoning effect. In serum with very high titers, prozoning may be observed.

2. Hemolyzed samples may have been used. Avoid using hemolyzed samples for testing.

3. Reagents not brought to room temperature. Cold reagents could give false

negative results.

All reagents must be brought to room temperature before

use.

Troubleshooting

Immutex

Problem: False positive results

Problem: False negative results

Serology/Immunology 645

RAPID TEST FOR IGM ANTIBODIES TO

LEPTOSPIRA: LEPTOSPIROSIS

(LEPTOCHEK WB) (DEVICE)

(Courtesy: Tulip Group of Companies)

Introduction

Leptocheck-WB is a rapid, self-performing, qualitative,

sandwich immunoassay for the detection of Leptospira

specific IgM antibodies in human serum/plasma or

whole blood specimen. It is useful for the serodiagnosis of

current or recent leptospirosis. The broadly reactive genus

specific antigen employed in the test allows the detection

of Leptospira infections caused by a wide range of strains

of different serovars.

Summary

Leptospira are actively motile, delicate spirochetes

possessing a large number of closely wound spirals and

characteristic hooked ends. There are several species of

Leptospira and they may be saprophytic or parasitic. They

can be distinguished only under dark ground illumination

in the living state or by electron microscopy. Leptospirosis

is a zoonotic disease of worldwide prevalence. Humans

are infected when the water contaminated by the urine of

carrier animals enters the body through cuts or abrasions

on the skin or through intact mucosa of the mouth, nose

or conjunctiva. Clinical symptoms include fever, chills,

headache, conjunctivitis, myalgia and Gl-related symptoms,

kidney infection is a common sequelae.

Diagnosis may be made by demonstration of Leptospira

microscopically in blood or urine, by isolating them in culture

or by inoculation of guinea pigs, or by serological tests.

Leptocheck-WB, qualitatively detects the presence

of IgM class of Leptospira specific antibodies in human

serum/plasma or whole blood specimen.

Principle

Leptocheck-WB utilizes the principle of immuno -

chromatography, a unique two-site immunoassay on a

membrane. As the test sample flows through the membrane

assembly of the test device, the anti-human IgM-colloidal

gold conjugate forms a complex with IgM antibodies in the

sample. This complex moves further on the membrane to

the test window ‘T’ where it is immobilized by the broadly

reactive Leptospira genus specific antigens coated on the

membrane, leading to the formation of a red to deep purple

colored band at the test region ‘T’ which confirms a positive

test result. Absence of this colored band in test region ‘T’

indicates a negative test result. The unreacted conjugate

and the unbound complex if any move further on the

membrane and are subsequently immobilized by the antirabbit antibodies coated on the control window ‘C’ of the

membrane assembly, forming a red to deep purple colored

band. The control band serves to validate the test results.

Reagents and Material Supplied

Each kit contains:

A. Individual pouches, each containing:

1. Test Device Membrane test assembly predispensed with Anti Human IgM-colloidal gold

conjugate, Leptospira genus specific antigens at

test window ‘T’ and anti-rabbit antiserum predispensed at the control window ‘C’.

2. Desiccant pouch

3. 5 µL sample loops.

B. Sample running buffer

C. Package insert.

Storage and Stability

The sealed pouches in the test kit and the kit components

may be stored between 4 and 30°C for the duration of the

shelf-life as indicated on the pouch.

Optional Material Required: 10 µL precision micropipettes.

Note

1. Forin vitro diagnostic use only. Notfor Medicinal Use.

2. Do not use beyond expiry date.

3. Read the instructions carefully before performing the

test.