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Limulus amebocyte lysate (LAL) is an aqueous extract of blood cells (amoebocytes) from the Atlantic horseshoe crab Limulus polyphemus. LAL reacts with bacterial endotoxin lipopolysaccharide (LPS), which is a membrane component of gram-negative bacteria. This reaction is the basis of the LAL test, which is widely used for the detection and quantification of bacterial endotoxins.

In Asia, a similar Tachypleus amebocyte lysate (TAL) test based on the local horseshoe crabs Tachypleus gigas or Tachypleus tridentatus is occasionally used instead. The recombinant factor C (rFC) assay is a replacement of LAL/TAL based on a similar reaction.

The LAL test

There…


Metformin, sold under the brand name Glucophage among others, is the first-line medication for the treatment of type 2 diabetes, particularly in people who are overweight. It is also used in the treatment of polycystic ovary syndrome. It is not associated with weight gain and is taken by mouth. It is sometimes used as an off-label augment to attenuate the risk of weight gain in people who take antipsychotics as well as phenelzine.

NAD+

Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two…


The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as indexed by Clarivate’s Web of Science. As a journal-level metric, it is frequently used as a proxy for the relative importance of a journal within its field; journals with higher impact factor values are given status of being more important, or carry more prestige in their respective fields, than those with lower values. …


The “valley of death” refers to the critical period between preclinical validation and clinical evaluation of CBTs (complex biological therapies), as a result of the drop-off in academic funding and the complex regulatory requirements.

Every year, hundreds of thousands of potential drugs die in the valley of death. That’s what academic scientists call the time between a basic science discovery (usually in academic labs) and the decision to commit resources to develop the idea into a drug (almost always by industry).

Many discoveries, for a variety of reasons, never clear that hurdle. In 2015, for example, scientific journals published 1.2…


Zotero is a free and open-source reference management software to manage bibliographic data and related research materials (such as PDF files). Notable features include web browser integration, online syncing, generation of in-text citations, footnotes, and bibliographies, as well as integration with the word processors Microsoft Word, LibreOffice Writer, and Google Docs. It is produced by the Center for History and New Media at George Mason University.

Using Zotero with Google Docs

Plugins for Zotero

Citation Style Language

The Citation Style Language (CSL) is an open XML-based language to describe the formatting of citations and bibliographies. Reference management programs using…


Chimeric antigen receptor T cells (also known as CAR T cells) are T cells that have been genetically engineered to produce an artificial T cell receptor for use in immunotherapy.

Senolytic

A senolytic (from the words senescence and -lytic, “destroying”) is among a class of small molecules under basic research to determine if they can selectively induce death of senescent cells and improve health in humans. A goal of this research is to discover or develop agents to delay, prevent, alleviate, or reverse age-related diseases. A related concept is “senostatic”, which means to suppress senescence.

Anti-apoptotic protein

A…


A telomere is a region of repetitive nucleotide sequences associated with specialized proteins at the ends of linear chromosomes. Although there are different architectures, telomeres, in a broad sense, are a widespread genetic feature most commonly found in eukaryotes. In most, if not all species possessing them, they protect the terminal regions of chromosomal DNA from progressive degradation and ensure the integrity of linear chromosomes by preventing DNA repair systems from mistaking the very ends of the DNA strand for a double strand break.

Telomerase

Telomerase, also called terminal transferase, is a ribonucleoprotein that adds a species-dependent telomere repeat…


A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell surface.

T cells are born from hematopoietic stem cells, found in the bone marrow. Developing T cells then migrate to the thymus gland to mature. T cells derive their name from this organ where they develop (or mature). After migration to the thymus, the precursor cells mature into several…


Terminal restriction fragment length polymorphism

Terminal restriction fragment length polymorphism (TRFLP or sometimes T-RFLP) is a molecular biology technique for profiling of microbial communities based on the position of a restriction site closest to a labelled end of an amplified gene. The method is based on digesting a mixture of PCR amplified variants of a single gene using one or more restriction enzymes and detecting the size of each of the individual resulting terminal fragments using a DNA sequencer. …


Gram stain or Gram staining, also called Gram’s method, is a method of staining used to distinguish and classify bacterial species into two large groups: gram-positive bacteria and gram-negative bacteria. The name comes from the Danish bacteriologist Hans Christian Gram, who developed the technique.

Gram staining differentiates bacteria by the chemical and physical properties of their cell walls. Gram-positive cells have a thick layer of peptidoglycan in the cell wall that retains the primary stain, crystal violet. Gram-negative cells have a thinner peptidoglycan layer that allows the crystal violet to wash out on addition of ethanol. They are stained…

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