difference Protocols

Category: Microscopy Protocols: Optical Microscopy Protocols

When imaging specimens in the optical microscope, differences in intensity and/or color create image contrast, which allows individual features and details of the specimen to become visible. Contrast is defined as the difference in light intensity between the image and the adjacent background relative to the overall background intensity. In general, a minimum contrast value of 0.02 (2 percent) is needed by the human eye to distinguish differences between the image and its background. - [Read Contrast in Optical Microscopy]

Category: Stem Cell Protocols: Stem Cell Isolation Protocols

The starting material for de novo isolation of stem cell lines can be either normal 3.5-days post coitum (dpc) expanded blastocysts or "delayed" blastocysts. Delayed blastocysts are usually collected 4-6 days after ovariectomy. For both groups of blastocysts, tissue culture procedures are similar. The only difference is the timing of the first disaggregation, because delayed blastocysts will initially grow more slowly. - [Read De Novo Isolation of Embryonic Stem (ES) Cell Lines from Blastocysts Protocol]

Category: Transfection Protocols

Polybrene and DMSO can be used to achieve stable transformation of several types of cells by plasmid DNA. The yield of transformants is up to 15-fold greater with Polybrene than with calcium phosphate-DNA coprecipitation. However, there is no difference between the two methods in the efficiency of transformation of cells by high-molecular-weight DNA. - [Read DNA Transfection Using Polybrene Protocol]

Category: Microinjection Protocols: Microinjection of Proteins Protocols

This protocol describes a method for microinjecting proteins into the nucleus or cytoplasm of adherent cells. Microinjection equipment can be obtained from a number of suppliers; this protocol has been used with the Narishige IM-200 air pressure regulator and the Leitz micromanipulator. Using this system, it is possible to microinject a constant volume within a 50% difference among cells. - [Read Microinjection of Protein Samples Protocol]

Category: Plant Biology Protocols: Arabidopsis Transformation Protocols

Protocol for a simplified Arabidopsis transformation. Found that the MS salts, hormone, etc. make no difference, that OD of bacteria doesn't make much of a difference, that vacuum doesn't even make much of a difference as long as you have a decent amount of surfactant present. Plant health is still a major factor - healthy fecund plants make a big difference! With this method you should be able to achieve transformation rates above 1%. - [Read Simple Arabidopsis Transformation Protocol]