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6.0 OPERATION INSTRUCTIONS
6.1 Instrument Anatomy
The basic anatomy of the Single Slide Automated Gram Stainer consists of four parts as described below:
Display screen – the screen that prompts which buttons to select for procedure steps.
Key Pad – the twelve button key pad used to select process options on the instrument.
Cuvette – holds the slide during the staining process.
Front panel – covers the reagent supply pumps and waste drain pumps.
6.2 Specimen Slide Preparation
6.2.1 If the culture is to be taken from a Petri dish or a slant culture tube, first add a drop or a few loops full of water on the slide and aseptically transfer a
minute amount of a colony on the Petri dish. Transfer a drop of the suspended culture to be examined on a slide with an inoculation loop. Note that only a
very small amount of culture is needed; a visual detection of the culture on an inoculation loop already indicates that too much is taken. If staining a clinical
specimen, smear a very thin layer onto the slide, using a wooden stick. Do not use a cotton swab as the cotton fibers may appear as artifacts. The smear should
be thin enough to dry completely within a few seconds. The stains will not penetrate thickly applied specimens, making interpretation very difficult.
6.2.2 Spread the culture with an inoculation loop to an even thin film over a circle of 1.5 cm in diameter, approximately the size of a dime.
Position the smear at least 3/4" below the frosted area. Labels should not extend below the frosted area.
6.2.3 Fixing the specimen causes the cells to adhere to the glass slide to make possible the subsequent rinsing of the smear with water without a significant loss
of cells. This can be accomplished by methanol fixation. For best results, it is required that the methanol method be used, rather than heat, since it
is superior in preventing lysis, distortion, or damage to the cells in clinical material. Red and white cells will not be harmed, whereas heat will distort
or disrupt the cells. Passing the slide over a flame is also not recommended.
Methanol fixed slides have been shown to retain two to ten times as many cells than with heat fixation.(1) In addition, Gram positive bacteria are much less
likely to become over-decolorized when fixed with methanol rather than heat.(2)
Methanol Fixation Procedure: Air-dry the specimen. If a heat block must be used, do not set the temperature above 40°C, and do not leave the slides on the
block for over an hour. It is extremely important that the specimen does not get damaged by excessive heat. Once fully dried, fix by submerging the slide into a
Coplin jar filled with methanol. Please ensure that the methanol covers the whole smear. Drain off remaining methanol without rinsing by tapping the bottom
edge of the slide to paper towel and allow slide to air dry. Do not apply heat after the methanol dries.
NOTE: Because the slide preparation technique can vary from institution to institution and technique is not always controllable (i.e., differences in smear
thickness, fixation techniques, drying time, specimen adherence to different types and brands of slides, etc.) rare instances of carryover from slide to slide have
been reported. The chance of this can be minimized by carefully following the instructions in this manual.
NOTE: For best results with this instrument use glass slides that are positively charged such as Cardinal Health™ Microscope Slide Charged Adhesion Frosted
25mm x 75mm 1mm (Cat. No. M6143) to increase specimen adhesion to the glass slide. The adhesion of the specimen can be variable, depending on the
specimen type, volume and its thickness. Lack of adhesion is most notable in blood or bloody culture smears, so it is mandatory to use chemically treated slides
that produce a positive electrical charge in order to enhance the specimen's attachment to the slide. Excessively thick smears can lead to a sloughing off of cells
from the slide. So it is important to prepare smears that are relatively thin with some transparency. Software and fluid flow design have been engineered to
minimize the occurrence, but rare occasions of carryover may still be possible depending on the differences in the user's slide and slide preparation techniques.
It is recommended to reconfirm the presence of low numbers of bacteria in traditionally sterile specimens (such as spinal or joint fluid) with manual staining and
culture results.
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CHBAGS_GramStainer_IFU.indd 8
Art specifications:
IFU/Manual - 8"Wx10"H
Do not alter art or size.
All art prints PMS 185 Red and
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AMS1800062
Rev. 0 2018-06
Single Slide Automated Gram Stainer User Manual
7/3/18 1:31 PM
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