All body discharges contain extraneous
materials, such as pus cells and mucus. Of interest,
however, are the types of bacteria that may be present.
The stained smear reveals only two features:
morphology and the staining characteristics of the
Positive identification requires
cultures and further studies.
Hospital Corpsmen should report only what
For example, Smear shows numerous
If two or more types of
bacteria are seen in a smear, the rule is to report them in
order of predominance. For example:
1. Numerous gram-positive cocci in clusters
2. Few gram-negative bacilli
Gram-positive organisms are easy to see because
they stain a deep blue or blue-black. Gram-negative
organisms stain a deep pink, but since the background
material is also pink, minute and detailed inspection is
necessary before reporting the results.
In the presence of gonorrhea, the smear will reveal
large numbers of pus cells with varying numbers of
intracellular and extracellular gram-negative,
bean-shaped cocci in pairs. Such a finding could be
considered diagnostic. It is important to point out that
only a few of the thousands of pus cells on the slide
may contain bacteria, and sometimes it requires
considerable search to find one.
principles and procedures for the Rapid
Plasma Reagin (RPR) Card Test and the
Monosticon DRI-DOT® Slide Test.
Serology consists of procedures by which antigens
and reacting serum globulin antibodies may be
measured qualitatively and quantitatively. Serologic
tests have been devised to detect either antigens
present or antibodies produced in a number of
Most tests are based on agglutination
reactions between an antigen and a specific antibody.
An antigen is a substance that, when introduced
into an individual who does not already possess that
substance, may stimulate the individuals cells to
produce specific antibodies that react to this substance
in a detectable way. The five basic characteristics of an
antigen are that it must be foreign to the body, it must
possess a high molecular weight, it must be
structurally stable, it must be complex, and it must
have a high specificity to stimulate tissues to produce a
defensive protein substance called an antibody.
Antibodies are the specific defensive proteins
produced when an antigen stimulates individual cells.
Antibodies are produced by the host in response to the
presence of an antigen and are capable of reacting with
antigens in some detectable way.
The antigen-antibody reaction takes place when
a reaction occurs between specific antibodies in the
plasma and the antigen present on cell surfaces.
Principles and procedures of two serologic tests,
the rapid plasma reagin (RPR) card test and the
Monosticon DRI-DOT® Slide Test are covered in the
RAPID PLASMA REAGIN (RPR)
The RPR Card test is a sensitive, easily performed
screening test for syphilis. The test is performed on
unheated plasma or serum. Everything needed for the
test is in a kit that is available commercially. This test
kit is very useful aboard ship and at small stations.
Principle of the RPR Card Test
In the RPR Card test method of syphilis detection, a
specific antigen (carbon-particle cardiolipin) detects
reagin, a substance present in the serum of persons
who are infected with syphilis. Specimens that contain
reagin cause formation of particles (called flocculation)
or coagulation of the carbon particles to occur on the
RPR Card antigen. Reactive specimens appear as black
clumps against a white background.
specimens appear as an even, light-gray color.
Materials Required for RPR Test
To perform an RPR Card test, the following
materials are required:
Serum samplevenous blood collected in tubes
unhemolyzed serum that has been separated
from the blood cells as soon after collection as
RPR Card Test Kit, which consists of the
RPR Card antigen suspension