Immunocytochemistry cell sample preparation

Raman spectroscopy can offer a number of advantages over traditional cell or tissue analysis techniques used in the field of TE (Table 18.1). Commonly used analytical techniques in TE include the determination of a specific enzyme activity (e.g. lactate dehydrogenase, alkaline phosphatase), the expression of genes (e.g. real-time reverse transcriptase polymerase chain reaction) or proteins (e.g. immunohistochemistry, immunocytochemistry, flow cytometry) relevant to cell behaviour and tissue formation. These techniques require invasive processing steps (enzyme treatment, chemical fixation and/or the use of colorimetric or fluorescent labels) which consequently render these techniques unsuitable for studying live cell culture systems in vitro. Raman spectroscopy can, however, be performed directly on cells/tissue constructs without labels, contrast agents or other sample preparation techniques. 

Immunocytochemistry can be a valuable tool for the determination of cellular contents from individual cell suspensions. Samples which can be analyzed include blood smears, aspirates, and swabs from any cellular site. Each sample is treated differently and yet all the methods are interchangeable. There is no one way to prepare these types of cell samples for immunocytochemical analysis. This chapter will deal with the most common forms of cell sample the swab, aspirate, smear, and touch preps. Blood can be analyzed as a smear but it presents more of a problem owing to the concentration of red blood cells. These cells have an oxidative type function and when using a peroxidase based detection system it can greatly interfere with the test. Concentrated cellular suspensions... 

Sample preparation is one of the most important steps in immunocytochemistry because it generally receives the least amount of planning. Unfortunately, few researchers understand how critical the first few steps in an immunocytochemistry experiment are. In fact, the quality of the cells and tissue and the ability to get good results are totally dependent on initial fixation. To put sample preparation in perspective, perhaps the best thing to do is focus on the conclusion of the experiment -the quality of final microscopic image. Good images only come from cells and tissues that are fixed properly. 

Importantly, while IHC represents an important tool for examination of healthy cells and tissues, it is also of fundamental importance in the diagnosis of disease (histopathology). When referring to cell preparations, IHC may be used interchangeably with the term immunocytochemistry (ICC). The following describes the use of IHC to examine a tissue sample. 

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