Iris Sample Processing StatSpin® CytoFuge 2 Compact Cytocentrifuge System - Manual (Page 8)

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Section
3
Sample Requirements/Preparation
Overview
The approximate cell concentration of the specimen should be established prior to slide preparation
on the CytoFuge 2. Samples containing higher than optimal cell concentration will produce slides
with cells too closely packed or overlapping. Samples containing too low a cell concentration will
yield slides where cells are difficult to find, count, or examine. The following is a general guideline for
sample concentration based on an average cell diameter of 10 µm:
Sample Concentration Recommendation
500 - 1500 cells/µL* Use optimum sample volume
Less than 500 cells/µL Pre-concentrate sample
More than 1500 cells/µL Dilute sample
* In samples known for low cell populations (e.g. CSF), 50-100 cell/µL will produce acceptable results.
CAUTION - Universal Precautions should be followed on all specimens, regardless of whether
a specimen is known to contain an infectious agent. (See references)
Sample volumes
Use the following guidelines for sample volumes in each of the CytoFuge 2 concentrators:
Max. Volume Range Optimum Volume Range
Filter Concentrator 50 to 500 µL 100 to 400 µL
One-well Cell Concentrator 300 to 1600 µL 400 to 800 µL
Three-well Cell Concentrator 50 to 400 µL 100 to 200 µL
Pre-concentration
For best results, samples low in cellular content should be pre-concentrated. For example, if the
original sample contains about 100 cells/µL, a 10x pre-concentration will provide the 1,000 cells/µL,
which is recommended for the CytoFuge 2.
To pre-concentrate a sample,
1. Transfer 10 mL of sample to a conical polypropylene centrifuge tube.
2. Spin the sample at 1000-1500 xg for 10-15 minutes in a conventional centrifuge.
3. Decant 9 mL of cell-free supernatant.
4. Mix the cell pellet and remaining supernatant by vortexing or agitation of the tube.
5. Pipette appropriate volume of the concentrated sample to CytoFuge concentrators.
Dilution
For best results, dilute samples with extremely high cell density. For most applications, buffered
saline or standard tissue culture media (e.g. Geys balanced salt solution), both with a drop or two of
bovine serum albumin (BSA), which promotes cell adhesion to the microscope slide, may be used
as a diluent.