Morphology of the mature neutrophil

These more mature cell types are incapable of division and are identified by their nuclear morphology, granule content and accumulation of glycogen particles. In a mature neutrophil there are 200-300 granules, with the specific granules being about twice as abundant as azurophilic granules. 

Microscopic examination of the mature neutrophils reveals two striking features a single multilobed nucleus and a dense, granular appearance of the cytoplasm (see Fig. 1.1a). The nucleus typically comprises two to four segments, and within this organelle the chromatin is coarsely clumped. Until recently, this abnormal chromatin structure was taken as evidence that the nucleus was transcriptionally inactive however, it is now appreciated that the mature neutrophil does perform active transcription ( 7.3), although rates of biosynthesis are somewhat lower than those observed in cells such as monocytes. There is no detectable nucleolus, so there can be only limited synthesis of ribosomal RNA in these cells. 

The most abundant organelles within the cytoplasm are the granules, which are membrane-bound organelles containing an array of antimicrobial proteins. As discussed above ( 2.4), three major types have been identified to date azurophilic, specific and gelatinase-containing granules. Additionally, newly-described structures called secretory vesicles have been identified. 

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