Cholesterol is an important lipid molecule in cell membranes and lipoproteins. Most of the professionals at CD BioGlyco are highly skilled in sterol lipids analysis. Welcome customers from all over the world to cooperate with us!

What Is Cholesterol?

Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell membranes. When chemically isolated, it is a yellowish crystalline solid. Cholesterol is the principal sterol synthesized by all animals. In vertebrates, hepatic cells typically produce the greatest amounts. It is absent among prokaryotes (bacteria and archaea), although there are some exceptions, such as Mycoplasma, which require cholesterol for growth.

Cholesterol is also a key component in lipoproteins, which are used to transport hydrophobic molecules (such as fats) in hydrophilic media, like blood. Lipoproteins, classified as very-low-density lipoprotein, low-density lipoprotein (LDL), intermediate-density lipoprotein, and high-density lipoprotein (HDL), consist of esterified and free cholesterol, proteins, phospholipids, and triglycerides. Cholesteryl ester transfer protein facilitates the transfer of cholesterol esters and triglycerides among different classes of lipoproteins.

Fig.1 LC-MS/MS analysis of cholesterol (Reginald & Chew, 2019)

Cholesterol Lipid Analysis Services

Cholesterol is a precursor of steroid hormones, bile acids, and vitamin D. Abnormal levels of cholesterol or its precursors have been observed in various human diseases, such as heart diseases, stroke, type II diabetes, brain diseases, and many others. Therefore, accurate quantification of cholesterol is important for individuals who are at increased risk for these diseases. CD BioGlyco provides multiple analytical methods for the analysis of cholesterol, including classical chemical methods, enzymatic assays, gas chromatography (GC), liquid chromatography (LC), mass spectrometry (MS), and ambient ionization mass spectrometry (AIMS). Our cholesterol lipid analysis technology includes but is not limited to:

• Modified Abell-Kendall method.
  It is a multi-step classical chemical method involving Liebermann-Burchard reaction for color development. It includes saponification of cholesterol ester with alcoholic potassium hydroxide, extraction of hydrolyzed cholesterol with hexane followed by evaporation of the solvent, and finally color development with acetic anhydride and concentrated sulfuric acid.
• Enzymatic assays.
  Those types of assays are based on the enzyme-coupled reaction to determine total cholesterol levels. At first, esterified cholesterol is hydrolyzed to free cholesterol by cholesterol esterase. The free cholesterol is subsequently oxidized to cholest-4-en-3-one by cholesterol oxidase. Hydrogen peroxide is produced in this reaction as a side product and can be easily detected using highly sensitive colorimetric or fluorometric probes.
• Gas and liquid chromatography.
  Chromatographic techniques such as gas and liquid chromatography are commonly used for cholesterol quantification. Those methods are widely accepted to be more reliable, sensitive, and accurate than the other methods. Additional selectivity is achieved because cholesterol is separated from interfering species (such as sterols) on chromatographic columns. Moreover, low volumes of samples are required for analysis.
• Electrospray ionization (ESI) tandem mass spectrometry.
  Cholesterol ester species tend to form stable ammonium adduct ions [M+NH₄]⁺ that can be successfully detected. Derivatization of free cholesterol is required to improve ionization efficiency in ESI-MS.
• Matrix-assisted laser desorption/ionization mass spectrometry (MALDI).
• Ambient ionization mass spectrometry (AIMS).
  Desorption electrospray ionization (DESI) and direct analysis in real time are two rapid AIMS-based technologies that can be directly used for quantitative cholesterol measurements and are more effective than direct ESI approaches for cholesterol ionization.

Advantages of Us

• Reliable and diverse cholesterol lipid analysis methods.
• Professional team, high-quality customized cholesterol lipid analysis services.
• Extensive experience in cholesterol lipid analysis.
• 24 hours after-sales service.

CD BioGlyco has many years of experience in lipidomics analysis services, which can provide you with detailed plans, implementation, and corresponding experiments reports. Whenever you need a solution for cholesterol lipid analysis, we will work closely with you to determine the research purpose and develop a customized plan. If you are interested in our services, please feel free to contact us, we are looking forward to being your indispensable assistant.

References:

1. Reginald, K.; Chew, F.T. The major allergen Der p 2 is a cholesterol binding protein. Scientific reports. 2019, 9(1): 1-8.
2. Li, L.H.; et al. Analytical methods for cholesterol quantification. Journal of food and drug analysis. 2019, 27(2): 375-386.