Fluorescent properties of histone-1-anilinonaphthalene 8-sulfonate complexes in the presence of denaturant agents: application to the rapid staining of histones in urea and Triton-urea-polyacrylamide gels

Rapid staining of proteins on polyacrylamide gels and nitrocellulose membranes using a mixture of fluorescent dyes

The present work describes a novel, fluorescence-based method for staining proteins on SDS-PAGE and membrane(s). In this method, proteins are stained using a mixed-dye (sulfo-rhodamine B and 1-anilino-8-naphthalene sulfonic acid (NH(4)(+))) solution. The mixed-dye staining protocol can detect proteins up to a concentration of 15 ng. This method is generally applicable to all proteins and is more sensitive than the conventional Coomassie blue method. The staining method is rapid and efficient. Staining-destaining of proteins using the mixed-dye protocol takes less than half an hour. Another interesting feature of the staining protocol described here is the applicability to the staining of proteins on nitrocellulose membranes.

Background-free, high sensitivity staining of proteins in one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gels using a luminescent ruthenium complex

SYPRO Ruby dye is a permanent stain comprised of ruthenium as part of an organic complex that interacts noncovalently with proteins. SYPRO Ruby Protein Gel Stain provides a sensitive, gentle, fluorescence-based method for detecting proteins in one-dimensional and two-dimensional sodium dodecyl sulfate-polyacrylamide gels. Proteins are fixed, stained from 3h to overnight and then rinsed in deionized water or dilute methanol/acetic acid solution for 30 min. The stain can be visualized using a wide range of excitation sources commonly used in image analysis systems including a 302 nm UV-B transilluminator, 473 nm second harmonic generation (SHG) laser, 488 nm argon-ion laser, 532 nm yttrium-aluminum-garnet (YAG) laser, xenon arc lamp, blue fluorescent light bulb or blue light-emitting diode (LED). The sensitivity of SYPRO Ruby Protein Gel Stain is superior to colloidal Coomassie Brilliant Blue (CBB) stain or monobromobimane labeling and comparable with the highest sensitivity silver or zinc-imidazole staining procedures available. The linear dynamic range of SYPRO Ruby Protein Gel stain extends over three orders of magnitude, which is vastly superior to silver, zinc-imidazole, monobromobimane and CBB stain. The fluorescent stain does not contain superfluous chemicals (formaldehyde, glutaraldehyde, Tween-20) that frequently interfere with peptide identification in mass spectrometry. While peptide mass profiles are severely altered in protein samples prelabeled with monobromobimane, successful identification of proteins by peptide mass profiling using matrix-assisted laser desorption/ionization mass spectrometry was easily performed after protein detection with SYPRO Ruby Protein Gel stain.

A thousand points of light: the application of fluorescence detection technologies to two-dimensional gel electrophoresis and proteomics

As proteomics evolves into a high-throughput technology for the study of global protein regulation, new demands are continually being placed upon protein visualization and quantitation methods. Chief among these are increased detection sensitivity, broad linear dynamic range and compatibility with modern methods of microchemical analyses. The limitations of conventional protein staining techniques are increasingly being encountered as high sensitivity electrophoresis methods are interfaced with automated gel stainers, image analysis workstations, robotic spot excision instruments, protein digestion work stations, and mass spectrometers. Three approaches to fluorescence detection of proteins in two-dimensional (2-D) gels are currently practiced: covalent derivatization of proteins with fluorophores, intercalation of fluorophores into the sodium dodecyl sulfate (SDS) micelle, and direct electrostatic interaction with proteins by a Coomassie Brilliant Blue-type mechanism. This review discusses problems encountered in the analysis of proteins visualized with conventional stains and addresses advances in fluorescence protein detection, including immunoblotting, as well as the use of charge-coupled device (CCD) camera-based and laser-scanner-based image acquisition devices in proteomics.

Rapid imaging, using a cooled charge-coupled-device, of fluorescent two-dimensional polyacrylamide gels produced by labelling proteins in the first-dimensional isoelectric focusing gel with the fluorophore 2-methoxy-2,4-diphenyl-3(2H)furanone

A new method for visualising proteins in two-dimensional polyacrylamide gels was developed. Proteins were labelled with the fluorophore 2-methoxy-2,4-diphenyl-3(2H)furanone (MDPF) while present in the first-dimensional gel after isoelectric focusing and subsequently electrophoresed into the second-dimensional gel. High resolution spot patterns were produced and compared with other methods of visualisation. A new rapid imaging system based on a cooled charge-coupled-device was used to view the two-dimensional fluorescent protein spot patterns. The method allows the immediate and rapid imaging of two-dimensional gels at the end of electrophoresis with no further processing.

A synthetic peptide to the predicted 6.9K translation product of the HindIII-H/EcoRI-D region of the AcNPV genome induces antibodies to the basic DNA-binding protein

The sequence of the HindIII-H/EcoRI-D region of the AcNPV genome revealed a 55 codon methionine-initiated open reading frame (Wilson, M.E., Mainprize, T.H., Friesen, P.D. and Miller, L.K., 1987, J. Virol. 61, 661-666). This open reading frame predicts a 6.9K translation product with an amino acid composition nearly identical to the basic virion DNA-binding protein. A synthetic peptide was prepared to a region of the predicted 6.9K protein and used to induce antibodies in rabbits. Western blots of viral proteins, infected cell-specific proteins (24 h p.i.), and basic chromatin-associated proteins (24 h p.i.) were probed with anti-6.9K antisera. In all immunoblots, the anti-6.9K antisera were specific for the basic DNA-binding protein. This investigation provides further evidence that the basic DNA-binding protein of the virion is a viral-encoded gene transcribed from the HindIII-H/EcoRI-D region of the genome.

Ion-enhanced fluorescence staining of sodium dodecyl sulfate-polyacrylamide gels using bis(8-p-toluidino-1-naphthalenesulfonate)

A method for the sensitive fluorescent staining of sodium dodecyl sulfate (SDS) gels that extends the applicability and sensitivity of existing procedures has been developed. SDS-protein complexes are able to bind the noncovalent hydrophobic probe, bis(8-p-toluidino-1-naphthalenesulfonate) (bisANS) with an increase in quantum yield that is considerably larger than that observed with the commonly used monomeric form, 1-anilinonaphthalene-8-sulfonic acid (1,8-ANS). The quantum yield of bisANS bound to the SDS-protein complex is greatly enhanced by incubation with one of a number of cations including potassium and barium. The use of bisANS with metal ion enhancements provides a method for staining SDS gels that can be more sensitive than commonly used methods based on the binding of Coomassie blue, and provides a simple and rapid method for the detection and quantitation of proteins. The use of metal ion enhancements also greatly increases the sensitivity of staining methods based on the use of 1,8-ANS. The present method is much more sensitive than previous noncovalent, flourescent, postelectrophoresis stains, but it retains their considerable advantages of speed, simplicity, and the ability to perform secondary procedures on the separated materials.