The study of acyl carrier proteins (ACP) can provide unique insights into bacterial bio-synthetic pathways due to their integral role of ferrying intermediate substrates to desired enzymes’ active sites. Understanding bacterial biosynthesis can broaden our abilities to synthesis unnatural bioproducts using the cell's machinery. e.Coli's fatty acid ACP is a model for understand the broad family of carrier proteins. One centrally important but poorly understood feature of ACPs is how they protect and present their growing substrates via “chain flipping”. Substrates are placed at the end of a phosphopantetheine (Ppant) arm of holo ACPs and depending on the carbon chain length, the arm can sequester itself in a hydrophobic cavity preventing degradation. Vibrational (infrared and Raman) spectroscopy is an extremely attractive ways to study this process due to the short time scale on which they operate. Vibrational probes of particular interest include isonitriles (which have a very strong, unique IR peak at 2150 cm-1), azides, and alkynes. Recent work points to a modified SFP ligation reaction as a highly effective and versatile method of attaching probe-labeled CoA derivatives to apo ACPs: the challenge is to synthesize the probe-labeled CoA's, which we have attempted using transamidation chemistry. Another, convergent strategy that we have adopted is to incorporate probes within the hydrophobic cavity of the ACP itself via the use of unnatural amino acids. Results from both strategies will be presented. Coupled with the placement of vibrational probes at the end of the Ppant arm, vibrational spectroscopic experiments can offer a well rounded image of ACP's dynamic nature as it interacts with itself and its catalytic partners.