{"id":2862,"date":"2026-05-14T13:43:49","date_gmt":"2026-05-14T17:43:49","guid":{"rendered":"https:\/\/www.lifetein.com\/blog\/?p=2862"},"modified":"2026-06-02T12:37:07","modified_gmt":"2026-06-02T16:37:07","slug":"fluorescent-labeling-with-fam","status":"publish","type":"post","link":"https:\/\/www.lifetein.com\/blog\/fluorescent-labeling-with-fam\/","title":{"rendered":"Fluorescent Labeling with FAM"},"content":{"rendered":"\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"1920\" height=\"1720\" src=\"https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/5-FAM.webp\" alt=\"FAM\" class=\"wp-image-2881\" srcset=\"https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/5-FAM.webp 1920w, https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/5-FAM-300x269.webp 300w, https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/5-FAM-768x688.webp 768w, https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/5-FAM-1024x918.webp 1024w, https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/5-FAM-1536x1376.webp 1536w, https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/5-FAM-335x300.webp 335w\" sizes=\"(max-width: 1920px) 100vw, 1920px\" \/><figcaption class=\"wp-element-caption\">5-FAM<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Fluorescent labeling with FAM (carboxyfluorescein)<\/strong>\u00a0has become a foundational technique for visualizing and tracking peptides in a wide range of biological systems. This\u00a0<strong>bright, green fluorophore<\/strong>\u00a0is prized for its\u00a0<strong>high quantum yield<\/strong>,\u00a0<strong>excellent photostability<\/strong>, and compatibility with common detection platforms like fluorescence microscopy and flow cytometry<a href=\"https:\/\/abclonalbio.com\/catalog-antibodies\/FITC5FAM6FAMRabbitmAb\/A22444\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>. As a standard tool for cellular imaging and molecular interaction studies, FAM-labeled peptides offer researchers high-sensitivity detection with minimal background interference. However, because FAM exists as two distinct isomers, <strong>5-FAM<\/strong>\u00a0and\u00a0<strong>6-FAM<\/strong>, understanding their subtle differences is essential for designing successful experiments.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h4 id=\"key-takeaways\" class=\"wp-block-heading\">Key Takeaways<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>FAM<\/strong>\u00a0is a bright green fluorophore (Ex\/Em ~490-495 nm \/ 515-520 nm) widely used for peptide labeling in microscopy and flow cytometry.<\/li>\n\n\n\n<li>The two isomers,\u00a0<strong>5-FAM<\/strong>\u00a0and\u00a0<strong>6-FAM<\/strong>, differ in their\u00a0<strong>chemical linkage position<\/strong>\u00a0to the peptide backbone, which can affect binding interactions in certain assays.<\/li>\n\n\n\n<li><strong>5-FAM is a single isomer<\/strong>, while\u00a0<strong>6-FAM<\/strong>\u00a0is often preferred for custom synthesis due to its commercial availability and effective linkage chemistry.<\/li>\n\n\n\n<li>Conjugation is typically achieved via\u00a0<strong>NHS ester chemistry<\/strong>\u00a0targeting primary amines or\u00a0<strong>maleimide chemistry<\/strong>\u00a0for thiol-specific labeling<a href=\"https:\/\/probes.bocsci.com\/product\/fam-nhs-ester-427211.html?nid=7533\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>.<\/li>\n\n\n\n<li>Spacers such as\u00a0<strong>Ahx (aminohexanoic acid)<\/strong>\u00a0or\u00a0<strong>\u03b2-alanine<\/strong>\u00a0are often incorporated to minimize steric interference between the bulky FAM dye and the peptide\u2019s biological activity<a href=\"https:\/\/www.lifetein.com\/Peptide-Synthesis-FITC-modification.html\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"fundamentals-of-fam\" class=\"wp-block-heading\">Fundamentals of FAM<\/h2>\n\n\n\n<h4 id=\"what-is-fam\" class=\"wp-block-heading\">What Is FAM?<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">FAM (carboxyfluorescein) is a\u00a0<strong>fluorescein derivative<\/strong>\u00a0that contains a carboxylic acid group, facilitating covalent conjugation to biomolecules. It exhibits\u00a0<strong>excitation and emission maxima<\/strong>\u00a0of approximately 490-495 nm and 515-520 nm, placing it in the green channel of most fluorescence detection systems<a href=\"https:\/\/probes.bocsci.com\/product\/fam-nhs-ester-427211.html?nid=7533\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>. This spectral profile is compatible with\u00a0<strong>488 nm argon-ion lasers<\/strong>, the standard excitation source for flow cytometers and confocal microscopes, making FAM an accessible and cost-effective option for routine imaging applications.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Furthermore, LifeTein offers FAM among its extensive range of fluorescent labeling services, alongside FITC, TAMRA, cyanine dyes, and Alexa Fluor dyes, enabling researchers to select the optimal label for their specific experimental design<a href=\"https:\/\/www.lifetein.com\/Peptide-Synthesis-FITC-modification.html\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>.<\/p>\n\n\n\n<h4 id=\"why-use-fam-for-peptide-labeling\" class=\"wp-block-heading\">Why Use FAM for Peptide Labeling?<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Several key attributes make FAM exceptionally suited for peptide research:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>High brightness<\/strong>\u00a0\u2013 provides strong signal even at low concentrations.<\/li>\n\n\n\n<li><strong>Good photostability<\/strong>\u00a0\u2013 maintains fluorescence under prolonged illumination.<\/li>\n\n\n\n<li><strong>pH sensitivity<\/strong>\u00a0\u2013 fluorescence is optimal in the range pH 7.5\u20138.5 but decreases below pH 7, making it ideal for physiological conditions<a href=\"https:\/\/www.eurogentec.com\/en\/catalog\/5-6-fam-1-modification~21667db5-ea44-4e7e-b529-a69ea5ae3f16\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>.<\/li>\n\n\n\n<li><strong>Wide compatibility<\/strong>\u00a0\u2013 works seamlessly with fluorescence microscopes, plate readers, and flow cytometers<a href=\"https:\/\/www.benchchem.com\/product\/b1574612\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>.<\/li>\n<\/ul>\n\n\n\n<h4 id=\"5fam-vs-6fam-a-critical-distinction-for-labeling\" class=\"wp-block-heading\">5-FAM vs. 6-FAM: A Critical Distinction for Labeling<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">A common point of confusion is the difference between\u00a0<strong>5-FAM<\/strong>\u00a0and\u00a0<strong>6-FAM<\/strong>. Both are\u00a0<strong>positional isomers<\/strong>\u00a0of carboxyfluorescein, differing only in where the carboxylic acid group is attached to the fluorescein core (C5 vs. C6 position). This difference in linkage position means that when conjugated to a peptide, the fluorophore is presented at a slightly different orientation relative to the biomolecule.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">While their fluorescence emission spectra are similar and both are effective for general labeling, research has demonstrated that\u00a0<strong>5-FAM and 6-FAM can display distinct trends in binding interactions<\/strong>\u00a0and functional assays. For instance, studies on FAM-labeled DNA nanoantennas showed that despite similar fluorescence emission, the two isomers exhibited different quenching upon protein binding and different transient fluorescence spikes during enzymatic hydrolysis<a href=\"https:\/\/preview-www.nature.com\/articles\/s41592-021-01355-5\/figures\/12\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>. Thus, for experiments where the fluorophore\u2019s spatial orientation may influence target engagement, the choice of isomer should be carefully considered.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Some providers note that\u00a0<strong>5-FAM is a single isomer<\/strong>, whereas\u00a0<strong>6-FAM<\/strong>\u00a0is often the default for custom oligonucleotide labeling due to its effective blockage of the 3\u2032 terminus from polymerase extension<a href=\"https:\/\/www.eurogentec.com\/en\/catalog\/5-6-fam-1-modification~21667db5-ea44-4e7e-b529-a69ea5ae3f16\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>. In peptide synthesis, both isomers are available, and many commercial facilities offer FAM in either form depending on the researcher\u2019s preference.<\/p>\n\n\n\n<h4 id=\"fam-vs-fitc-what-is-the-difference\" class=\"wp-block-heading\">FAM vs. FITC: What Is the Difference?<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Another important distinction is between\u00a0<strong>FAM (carboxyfluorescein)<\/strong>\u00a0and\u00a0<strong>FITC (fluorescein isothiocyanate)<\/strong>. While both are green fluorophores with similar spectral properties, their conjugation chemistries differ. FAM typically contains a carboxylic acid group and is activated as an\u00a0<strong>NHS ester<\/strong>\u00a0for amine coupling. In contrast, FITC contains an isothiocyanate group that reacts directly with amines via a thiourea linkage. Observations suggest that\u00a0<strong>FITC-labeled peptides tend to deteriorate more quickly than FAM conjugates<\/strong>, making FAM the preferred choice for long-term stability.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/www.lifetein.com\/peptide_synthesis_services.html?_gl=1*15bjc7l*_gcl_aw*R0NMLjE3NTIyNTk1NTEuQ2p3S0NBanc3TUxEQmhBdUVpd0FJZVhHSVpVMXFSOXh4MzJEX3d6U2NYYUx2aWhzLWYzMU1FZ3VOSDRhcW41NUJtZmM1RnN3MkdVR0tSb0NCS01RQXZEX0J3RQ..*_gcl_au*NzY2NTIxODguMTc1MTUyMjM4MQ..&amp;_ga=2.129734156.1835841867.1753856001-90406248.1735925224\" target=\"_blank\" rel=\"noopener\">Find out more about peptide synthesis here<\/a>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"conjugation-chemistries-and-protocols\" class=\"wp-block-heading\">Conjugation Chemistries and Protocols<\/h2>\n\n\n\n<h4 id=\"nhs-ester-coupling-to-primary-amines\" class=\"wp-block-heading\">NHS Ester Coupling to Primary Amines<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">The most common method for FAM conjugation is via\u00a0<strong>NHS ester chemistry<\/strong>\u00a0(5\/6-carboxyfluorescein succinimidyl ester, FAM-NHS ester). In this approach, the NHS ester reacts efficiently with\u00a0<strong>primary amines<\/strong>, such as the \u03b5-amino group of lysine side chains or the N-terminal amine of the peptide, to form a chemically stable amide bond<a href=\"https:\/\/probes.bocsci.com\/product\/fam-nhs-ester-427211.html?nid=7533\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>. Typical protocols involve adding the FAM-NHS ester to the peptide at a 4\u201320:1 molar ratio in a pH 8.0\u20138.5 buffer (e.g., phosphate buffer or sodium bicarbonate) and incubating at room temperature for 2\u20134 hours. The reaction is then quenched with Tris or glycine, and the labeled peptide is purified by HPLC.<\/p>\n\n\n\n<h4 id=\"maleimide-coupling-to-thiols\" class=\"wp-block-heading\">Maleimide Coupling to Thiols<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">For site-specific labeling of cysteine residues,\u00a0<strong>FAM maleimide<\/strong>\u00a0(6-isomer) is employed. The maleimide group reacts specifically with free sulfhydryl groups (-SH) at pH 6.5\u20137.5, forming a stable thioether bond<a href=\"https:\/\/www.benchchem.com\/product\/b1574612\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>. This method provides precise control over labeling position, as cysteines are less common in native sequences and can be strategically introduced during peptide design.<\/p>\n\n\n\n<h4 id=\"spacers-to-reduce-steric-hindrance\" class=\"wp-block-heading\">Spacers to Reduce Steric Hindrance<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Given the bulky nature of the FAM fluorophore, incorporating a short spacer between the dye and the peptide core can mitigate\u00a0<strong>steric interference<\/strong>\u00a0and preserve biological activity. Common spacers include\u00a0<strong>6-aminohexanoic acid (Ahx)<\/strong>\u00a0and\u00a0<strong>\u03b2-alanine<\/strong><a href=\"https:\/\/www.lifetein.com\/Peptide-Synthesis-FITC-modification.html\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>. LifeTein has described the use of Ahx spacers in N-terminal FITC-labeled peptides to achieve successful intracellular delivery for super-resolution imaging<a href=\"https:\/\/www.lifetein.com\/Peptide-Synthesis-FITC-modification.html\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>. Similarly, PEG-based spacers (e.g., PEG6) have been employed in FAM-labeled cell-penetrating peptides to maintain activity and enable cellular uptake<a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC6044864\/?report=classic\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>.<\/p>\n\n\n\n<h4 id=\"purification-and-validation\" class=\"wp-block-heading\">Purification and Validation<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Following conjugation,\u00a0<strong>reverse-phase HPLC<\/strong>\u00a0is used to separate the labeled peptide from unreacted dye and truncated products, achieving purities exceeding 95-98%. Analytical techniques such as\u00a0<strong>mass spectrometry (MS)<\/strong>\u00a0confirm the correct molecular weight of the conjugate, ensuring proper labeling.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" width=\"1920\" height=\"1505\" src=\"https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/6-FAM.webp\" alt=\"\" class=\"wp-image-2883\" srcset=\"https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/6-FAM.webp 1920w, https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/6-FAM-300x235.webp 300w, https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/6-FAM-768x602.webp 768w, https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/6-FAM-1024x803.webp 1024w, https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/6-FAM-1536x1204.webp 1536w, https:\/\/www.lifetein.com\/blog\/wp-content\/uploads\/2026\/05\/6-FAM-383x300.webp 383w\" sizes=\"(max-width: 1920px) 100vw, 1920px\" \/><figcaption class=\"wp-element-caption\">6-FAM<\/figcaption><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"applications-of-famlabeled-peptides\" class=\"wp-block-heading\">Applications of FAM-Labeled Peptides<\/h2>\n\n\n\n<h4 id=\"livecell-imaging-and-internalization-studies\" class=\"wp-block-heading\">Live-Cell Imaging and Internalization Studies<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">FAM-labeled peptides are indispensable tools for tracking\u00a0<strong>cellular uptake and intracellular trafficking<\/strong>. For example, FAM-conjugated ovalbumin peptide (Fam-ova, SIINFEKL) has been widely used to study MHC-I antigen presentation and visualize cytosolic antigen release via confocal microscopy<a href=\"https:\/\/www.benchchem.com\/product\/b15138986\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>. Similarly, FAM-labeled cell-penetrating peptides (e.g., TAT-derived conjugates) have enabled real-time monitoring of peptide internalization<a href=\"https:\/\/pmc.ncbi.nlm.nih.gov\/articles\/PMC6044864\/?report=classic\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>.<\/p>\n\n\n\n<h4 id=\"flow-cytometry-and-receptor-binding-assays\" class=\"wp-block-heading\">Flow Cytometry and Receptor Binding Assays<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">The green fluorescence of FAM is readily detected by standard flow cytometers, making it ideal for quantifying\u00a0<strong>peptide-receptor interactions<\/strong>\u00a0and\u00a0<strong>competitive binding assays<\/strong>. FAM-labeled probes have been used to measure binding affinities in microscale thermophoresis (MST) and fluorescence polarization-based assays<a href=\"https:\/\/db.indra.bio\/statements\/from_hash\/-705057740713536?format=html\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>.<\/p>\n\n\n\n<h4 id=\"fretbased-assays-and-enzyme-substrate-design\" class=\"wp-block-heading\">FRET-Based Assays and Enzyme Substrate Design<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">FAM also serves as an excellent\u00a0<strong>donor fluorophore in FRET (F\u00f6rster Resonance Energy Transfer) pairs<\/strong>. When paired with an appropriate acceptor dye, such as TAMRA or Dabcyl, FAM-labeled peptides enable real-time monitoring of protease activity, conformational changes, and molecular interactions within 1\u201310 nm distances<a href=\"https:\/\/www.benchchem.com\/product\/b1574612\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>. This approach is widely used in high-throughput screening and mechanistic enzymology.<\/p>\n\n\n\n<h4 id=\"antibody-and-immunoassay-development\" class=\"wp-block-heading\">Antibody and Immunoassay Development<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Because FAM is a well-defined hapten, high-quality antibodies are commercially available for detecting FAM-labeled peptides in immunoassays. For instance, the FITC\/5-FAM\/6-FAM Rabbit mAb (A22444) recognizes both FAM isomers and offers high sensitivity for Western blotting, ELISA, and IHC applications<a href=\"https:\/\/abclonalbio.com\/catalog-antibodies\/FITC5FAM6FAMRabbitmAb\/A22444\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"frequently-asked-questions-faq\" class=\"wp-block-heading\">Frequently Asked Questions (FAQ)<\/h2>\n\n\n\n<h4 id=\"what-is-the-difference-between-5fam-and-6fam\" class=\"wp-block-heading\">What is the difference between 5-FAM and 6-FAM?<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">The two are\u00a0<strong>positional isomers<\/strong>\u00a0of carboxyfluorescein, differing only in the location of the carboxylic acid group (C5 versus C6 position). While their fluorescence emission spectra are nearly identical, research has shown that they can exhibit\u00a0<strong>different binding interactions<\/strong>\u00a0in certain biological assays, such as protein binding and enzymatic hydrolysis<a href=\"https:\/\/preview-www.nature.com\/articles\/s41592-021-01355-5\/figures\/12\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>. Therefore, the choice of isomer should be guided by the specifics of your experiment.<\/p>\n\n\n\n<h4 id=\"how-do-i-choose-between-fam-and-fitc-for-labeling\" class=\"wp-block-heading\">How do I choose between FAM and FITC for labeling?<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">FAM (carboxyfluorescein) and FITC (fluorescein isothiocyanate) share similar spectral properties, but their conjugation chemistries differ. FAM is typically activated as an NHS ester for amine coupling, whereas FITC reacts directly with amines via an isothiocyanate group. Notably,\u00a0<strong>FAM-labeled peptides tend to be more stable<\/strong>\u00a0than their FITC-conjugated counterparts. For long-term experiments requiring robust stability, FAM is therefore preferred.<\/p>\n\n\n\n<h4 id=\"can-i-purchase-custom-famlabeled-peptides-for-my-research\" class=\"wp-block-heading\">Can I purchase custom FAM-labeled peptides for my research?<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">Yes. Specialized providers such as\u00a0<strong>LifeTein<\/strong>\u00a0offer custom synthesis of FAM-labeled peptides with high purity (>98%) and rigorous analytical validation. Their services include choices between 5-FAM and 6-FAM, optional spacers (Ahx, \u03b2-Ala), and a variety of conjugation positions (N-terminus, lysine side chain, cysteine-specific labeling)<a href=\"https:\/\/www.lifetein.com\/Peptide-Synthesis-FITC-modification.html\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>.<\/p>\n\n\n\n<h4 id=\"what-buffers-should-i-use-when-working-with-famlabeled-peptides\" class=\"wp-block-heading\">What buffers should I use when working with FAM-labeled peptides?<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">FAM fluorescence is optimal between pH 7.5 and 8.5 and decreases sharply below pH 7<a href=\"https:\/\/www.eurogentec.com\/en\/catalog\/5-6-fam-1-modification~21667db5-ea44-4e7e-b529-a69ea5ae3f16\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a>. Therefore, neutral to slightly alkaline buffers (e.g., PBS at pH 7.4 or 8.0) are recommended for experiments involving FAM-labeled peptides. Stock solutions should be prepared in DMSO, as FAM is highly soluble in this organic solvent.<\/p>\n\n\n\n<h4 id=\"how-should-i-store-famlabeled-peptides-to-maintain-stability\" class=\"wp-block-heading\">How should I store FAM-labeled peptides to maintain stability?<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">FAM-labeled peptides should be stored as lyophilized solids at -20\u00b0C, protected from light. Once reconstituted in aqueous buffer, they should be used promptly and kept on ice. Avoid repeated freeze-thaw cycles, as these may degrade the fluorescent signal.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<h2 id=\"references\" class=\"wp-block-heading\">References<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Harroun, S. G., Lauzon, D., Ebert, M. C. C. J. C., Desrosiers, A., Wang, X., &amp; Vall\u00e9e-B\u00e9lisle, A. (2021). Monitoring protein conformational changes using fluorescent nanoantennas. Nature Methods, 19(1), 71\u201380. https:\/\/doi.org\/10.1038\/s41592-021-01355-5<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Okuda-Shinagawa, N. M., Moskalenko, Y. E., Junqueira, H. C., Baptista, M. S., Marques, C. M., &amp; Machini, M. T. (2017). Fluorescent and Photosensitizing Conjugates of Cell-Penetrating Peptide TAT(47-57): Design, Microwave-Assisted Synthesis at 60 \u00b0C, and Properties. ACS Omega, 2(11), 8156\u20138166. https:\/\/doi.org\/10.1021\/acsomega.7b01127<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Fluorescent labeling with FAM (carboxyfluorescein)\u00a0has become a foundational technique for visualizing and tracking peptides in a wide range of biological systems. This\u00a0bright, green fluorophore\u00a0is prized for its\u00a0high quantum yield,\u00a0excellent photostability, and compatibility with common detection platforms like fluorescence microscopy and &hellip; <a href=\"https:\/\/www.lifetein.com\/blog\/fluorescent-labeling-with-fam\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":6,"featured_media":2881,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[4],"tags":[],"class_list":["post-2862","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-peptide_synthesis"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 4.9.9 - aioseo.com -->\n\t<meta name=\"description\" content=\"FAM is a green 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