<p><span style="font-size:14px">For the analysis of complex biological samples, a reduction of sample complexity is required. This can be performed off-line by one-dimensional&nbsp;or two-dimensional&nbsp;separation. More recently, on-line methods have been developed where individual peptides (in bottom-up proteomics approaches) are separated using </span>Reversed-phase chromatography&nbsp;and then directly ionized using ESI;&nbsp;the direct coupling of separation and analysis explains the term on-line&nbsp;analysis.</span></p>

<h3>3)<strong> High-throughput proteomic technologies</strong></h3> <p>Proteomics has steadily gained momentum over the past decade with the evolution of several approaches. Few of these are new and others build on traditional methods. Mass spectrometry-based methods and micro arrays are the most common technologies for large-scale study of proteins.</p> <h4><strong>Reverse-phased protein microarrays</strong></h4> <p>This is a promising and newer microarray application for the diagnosis, study and treatment of complex diseases such as cancer. The technology merges laser capture microdissection (LCM)&nbsp;with micro array technology, to produce reverse phase protein microarrays. In this type of microarrays, the whole collection of protein themselves are immobilized with the intent of capturing various stages of disease within an individual patient. When used with LCM, reverse phase arrays can monitor the fluctuating state of proteome among different cell population within a small area of human tissue. This is useful for profiling the status of cellular signaling molecules, among a cross section of tissue that includes both normal and cancerous cells. This approach is useful in monitoring the status of key factors in normal prostate epithelium and invasive prostate cancer tissues. LCM then dissects these tissue and protein lysates were arrayed onto nitrocellulose slides, which were probed with specific antibodies. This method can track all kinds of molecular events and can compare diseased and healthy tissues within the same patient enabling the development of treatment strategies and diagnosis. The ability to acquire proteomics snapshots of neighboring cell populations, using reverse phase microarrays in conjunction with LCM has a number of applications beyond the study of tumors. The approach can provide insights into normal physiology and pathology of all the tissues and is invaluable for characterizing developmental processes and anomalies.</h3p>