MES is a buffering agent used in biochemistry and molecular biology that was selected and described by Good et al. It is a zwitterionic, morpholinic buffer that is useful for a pH range of 5.5 – 6.7 and commonly used for cell culture media, as a running buffer in electrophoresis, and for protein purification in chromatography. MES lacks the ability to form a complex with most metal ions and is recommended for use as a non-coordinating buffer in solutions with metal ions. MES is often used in buffered culture media for bacteria, yeast, and mammalian cells. It is toxic towards plants at high concentrations, but can be used in culture media at lower concentrations for plants. Due to low ionic mobility, MES is regarded as an excellent buffer for use in capillary electrochromatography. MES is often employed as a substitute for the highly toxic cacodylate, as well as a substitute for the non-zwitterionic buffers citrate and malate. MES complexes with some organotin(IV) molecules that are being explored as antitumor agents.

MOPS is a buffering agent used in biochemistry and molecular biology that was selected and described by Good et al. It is a zwitterionic, morpholinic buffer that is useful for a pH range of 6.5 – 7.9 and commonly used for cell culture media, as a running buffer in electrophoresis, and for protein purification in chromatography. MOPS lacks the ability to form a complex with most metal ions and is recommended for use as a non-coordinating buffer in solutions with metal ions.

Nickel Agarose Resin is available in bulk or in prepacked columns. It has a binding capacity of >25 mg/ml with approximately 60 kDa protein. In addition, it allows for purification of proteins under native or denaturing conditions. GoldBio Nickel Agarose works very well with the His-Tag Buffer Set.

IDA cross-linked Agarose resin consists of iminodiacetic acid groups ligated by stable ether linkages via a spacer arm. IDA is a tridentate chelating agent, covalently coupled to cross-linked agarose beads. This resin is loaded with Ni2+. The resulting, ready-to-use resin is ideal for rapid purifications of His-tagged proteins.

Affinity Chromatography is based on the interaction between certain superficial protein residues (histidines, cysteines and to a lesser extent tryptophans), with transition metal cations, forming chelates.

Nitrotetrazolium Blue (NBT) is used in combination with 5-bromo-4-chloro-3-indoxyl phosphate (BCIP) to detect alkaline phosphatase activity in blotting techniques and in situ hybridization chemistry. BCIP acts as the substrate for alkaline phosphatase, and the oxidizing reagent NBT enhances the purple-brown final color of the precipitates at the reaction sites.

NBT has also been used with X-Gal,or Salmon-Gal to speed up and enhance colony screening.

Nourseothricin is a broad-spectrum antibiotic derived from Streptomyces noursei. In addition to being effective on prokaryotic cells of gram-positive and gram-negative bacteria, various fungi including Candida albicans, and certain DNA and RNA viruses, it is also effective on eukaryotic cells of higher eukaryotes. It has been used as a selection agent for cells containing the gene conferring resistance to it.

GoldBio nourseothricin is a mixture of four streptothricin compounds: D and F (>85%) as well as C and E (<15%).

PMSF is a serine protease inhibitor that irreversibly inhibits serine proteases by sulfonylation of the serine residue in the active site of the protease. It is widely used in protocols for the isolation of proteins.

PMSF is inactivated in aqueous solutions. The rate of inactivation increases with increasing pH and is faster at 25°C than at 4°C. The half-life of a 20mM aqueous solution of PMSF is ~35 minutes at pH 8.0. This short half-life means that aqueous solutions of PMSF can be safely discarded after they have been rendered alkaline (pH >8.6) and stored for several hours at room temperature.

Proteinase K is a highly reactive nonspecific serine protease that belongs to the subtilisin family of proteins. It cleaves at the carboxylic acid side of aliphatic, aromatic, or hydrophobic amino acids. Proteinase K is capable of inactivating RNases and DNases and is used in the isolation or preparation of high molecular weight nucleic acids. Proteinase K is also useful for helping to characterize enzymes, due to its cleavage specificity. This enzyme was designated proteinase K because of its ability to hydrolyze keratin. Proteinase K is stable in a wide variety of detergents and buffer salts and at various temperatures and pH. The isoelectric point of proteinase K is 8.9.

Puromycin is an aminonucleoside antibiotic that causes early chain termination within the ribosome during translation. This inhibition of translation is effective in both in vivo and in vitro applications, making it an ideal tool for protein synthesis studies. While selection for E. coli cells is possible with puromycin, it is more commonly and effectively used for mammalian cell selection.

The growth of bacteria, protozoa, algae and mammalian cells is quickly halted by puromycin. However, cells with the pac gene have resistance. Its gene product is puromycin-N-acetyl-transferase which inactivates puromycin through acetylation.

Research has shown puromycin to be effective against certain tumors.

The ReadyLadder™ 1 kb DNA Ladder from GoldBio offers a convenient, ready-to-use solution for accurate DNA sizing in agarose gel electrophoresis. Featuring 13 defined bands spanning 250 bp to 10 kb, it provides the resolution needed for routine molecular biology experiments.

For easy visualization, the 1 kb and 3 kb bands are presented with greater intensity, ensuring fast orientation on the gel. With each load containing 0.5 μg of DNA, users can not only determine fragment size but also estimate DNA quantity by comparing band intensity. Premixed with Xylene cyanol FF and Bromophenol blue tracking dyes, this ladder simplifies workflows by allowing direct gel loading and real-time tracking of DNA migration. Reliable, consistent, and stable during shipping and storage, it’s an essential tool for accurate DNA analysis.

GoldBio’s ReadyLadder™ 1 kb PLUS™ DNA Ladder is a reliable, ready-to-use molecular weight marker designed for accurate sizing of medium-to-large DNA fragments. Composed of 14 distinct bands ranging from 250 bp to 25 kb, this ladder provides excellent coverage for routine electrophoresis.

To simplify interpretation, it includes two enhanced reference bands (3 kb and 1 kb) that stand out for quick identification. The ladder is premixed with loading buffer, containing Xylene cyanol FF and Bromophenol blue tracking dyes, enabling direct gel loading and real-time monitoring of DNA migration. Stable for ambient-temperature shipping and long-term storage, this ladder offers sharp, consistent bands and dependable performance for everyday molecular biology workflows.

GoldBio’s ReadyLadder™ 100 bp DNA Ladder is a convenient, ready-to-use molecular weight marker designed for accurate sizing of small DNA fragments. Composed of 11 defined bands ranging from 100 bp to 1,500 bp, this ladder is ideal for applications requiring high resolution of low–molecular weight DNA.

The 1,500 bp and 500 bp bands are intensified, giving you clear visual markers that make gel interpretation straightforward. With 0.5 μg of DNA per load, the ladder not only supports accurate fragment size determination but also provides a convenient way to estimate sample quantities by comparing band intensity. Because it is premixed with Orange G and Xylene cyanol FF tracking dyes, you can load it directly onto the gel and follow migration in real time. This ladder is designed for sharp, reproducible banding and long-term stability.

GoldBio’s ReadyLadder™ 100 bp PLUS™ DNA Ladder is a versatile, ready-to-use molecular weight marker designed for sizing small- to mid-range DNA fragments in agarose gel electrophoresis. With 12 clearly defined bands spanning 100 bp to 3,000 bp, this ladder is well-suited for applications that require precision across a broader range of low–molecular weight DNA. 

To simplify gel analysis, the 500 bp and 1,500 bp bands are enhanced in intensity, providing instant reference points during runs. Each load contains 0.5 μg of DNA, allowing researchers to approximate DNA quantity in experimental samples through direct band comparison. Pre-formulated with Orange G and Xylene cyanol FF tracking dyes, this ladder is optimized for direct gel loading and real-time visualization of migration. Its sharp banding patterns, ease of use, and shipping stability make it a dependable tool for everyday molecular biology workflows.