Most researchers would agree that manually performing a hundred or so plasmid preps after a low-efficiency cloning stifles the spirit of exploration that attracted them to science. Minipreps don't end with merely being tedious, repetitive, and time consuming--frequent exposure to hazardous chemicals adds to the misery. However, minipreps are a necessary evil in research, and the number of sequencing templates to prepare never seems to dwindle. For example, a small lab running four sequencing gel

Micromanipulator Tables In the early 1970s, researchers showed that macromolecules retained activity when injected into living cells. Since then, studies involving the activity or fate of any number of natural and synthetic macromolecules as well as transplanted organelles have created an informative field. Injected material can be studied directly, or longer-term effects such as transformation can be monitored; with some materials it is even possible to reisolate and characterize the injected m

MALDI-TOF Table Micromass' laser-addressable sample array target for MALDI Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry has become, in recent years, a tool of choice for large-molecule analyses, especially for proteins. Published applications address protein and nucleic acid sequence, structure, purity, heterogeneity, cleavage, posttranslational modification, and a host of other molecular characteristics that are often difficult to study

Date: May 24, 1999Microarray Products and Services GSI Lumonics Excitable Dyes I purified the DNA, ligated it, and transformed it; the gene has to be here somewhere!" In the days before positive selection vectors, a researcher might have screened thousands of clones by hand with an oligo just to find one elusive insert. Today's DNA array technology reverses that approach. Instead of screening an array of unknowns with a defined probe--a cloned gene, PCR product, or synthetic oligonucleotide--e

Date: April 12, 1999Table of DNA Sequencers LI-COR's IR2 Automated DNA Sequencer The first time I ran a sequencing gel using 35S rather than 32P, I was in heaven. The bands on the autoradiogram were incredibly sharp, the background was amazingly clean, and my read length increased by close to 20% to just over 100 bases. Things just couldn't get any better than that! In 1994, The Scientist reviewed the state of DNA sequencing technology and made some predictions about what might be coming next

Date: February 1, 1999Fusion/Tag Proteases TableProteolytic Enzymes TableTable 3Table 4 A proteome analysis aims to characterize all proteins expressed by an organism or tissue. The next step will be to correlate a protein profile with the appropriate genome, and beyond that researchers will want to understand the correlations between levels of proteins, co- and post-translational modifications, and cell or tissue activity. Many of the technologies that are necessary to realize this goal are de

Date: September 28, 1998 Filtration Table An article on filters? Nah, filters are too simple. You put a small paper cone in the filter holder, add coffee, and pour on hot water. Drip, drip, drip, and the coffee's ready. That's all there is to it. But hold on a minute. There are thirty grades of Whatman standard filter paper alone, and even if we restrict ourselves to a biological laboratory, we have depth filters and screen filters; filters with different pore sizes that are tightly or loosely

Date: June 22, 1998Table 1:Paramagnetic Particles, Table 2:Primary Antibodies Magnetic separations in biology and biotechnology have diversified in recent years, leading to a bewildering array of different particles, affinity mechanisms, and processes. Applications in the nucleic acid realm include products for total and poly(A)+ mRNA isolation from cells or previously purified total RNA preparations, solid-phase cDNA library construction, double-stranded and single-stranded DNA purification, s

You might think there couldn't be anything new in size exclusion chromatography. Think again. Princeton Separations' CentriSpin columns are the latest addition to a variety of commercially available micro- and mini-spin columns. Three CentriSpin columns-- CentriSpin-10, CentriSpin-20, and CentriSpin-40, each with a different exclusion point--allow for a variety of applications. Princeton Separations' CentriSpin Columns These new columns contain a crosslinked dextran-polymer gel-filtration ma