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Originally published Mar 8, 2016 and last updated Sept 3, 2020 by Nyla Naim.

Scientists around the world have been making major improvements to CRISPR technology since its initial applications for genome engineering in 2012.  Many of these advances have stemmed from the goal of reducing off-target Cas9 activity. The use of nickases, prime editing, anti-CRISPR proteins, and other techniques all aim to improve targeting specificity or reduce the duration of Cas9 activity. 

The field of optogenetics is renowned for enabling precise temporal and spatial control. Optogenetics uses genetically encoded tools, such as microbial opsins, to control cellular activities using light. In 2015, scientists combined CRISPR and optogenetic techniques to develop a variety of photoactivatable CRISPR tools. These tools allow scientists to use light to externally control the location, timing, and reversibility of the genome editing process. Read on to learn about the various light-controlled CRISPR tools available to researchers - some readily found at Addgene.

Chemogentic and optogenetic technologies have pushed the boundaries in neuroscience by granting targeted control over neuronal activity. While they serve similar purposes, both techniques offer researchers different advantages and limitations. 

The four main factors in which chemogenetics and optogenetics differ are:

• Timing
• Targeted manipulation
• Controlling stimulation
• Invasiveness 

Choosing the best set of tools therefore depends on what you are looking to study.

It’s time to choose your own protein purification adventure. You want to purify your favorite protein (YFP). You have two options: 

Option #1: Affinity tag purification

You tag YFP and use an affinity column for purification. After binding YFP to the column, you wash several times to remove non-specific proteins, and then elute YFP. 

Option #2: Opto-Nanobodies (OptoNBs) purification

You skip adding a tag to YFP and instead use OptoNBs. You fill a column with OptoNB coated beads and wrap the column with blue LED lights. When you switch off the lights, OptoNBs bind YFP and non-specific proteins flow through. To elute YFP, you turn on the blue lights.

Which option do you choose? 

This post was contributed by Alessia Armezzani, scientific communication manager at genOway.

A few decades ago, the brain remained elusive, not from a lack of intellectual curiosity on the part of scientists but, rather, from the limited technologies available. Over the past few years, however, remarkable technological advances have taken researchers to the threshold of a revolution in modern neuroscience, an era in which technologies like FLEx and optogenetics meet, allowing scientists to investigate the fundamental basis of both brain function and dysfunction.

First, let’s start with the basics: What is optogenetics?

Optogenetics, the use of light sensitive proteins (opsins) to manipulate cell activity, enables researchers to silence or incite neuronal firing and study subsequent effects on behavior. The system is an especially powerful tool for in vivo behavioral studies because it is non-invasive and offers a high degree of control over time and space.

Zebrafish have become a popular model organism because their larval stage lends itself well to studies of neuroscience. The larvae of zebrafish are translucent and allow for noninvasive live imaging with fluorescent tags and activation of light sensing proteins. Furthermore, during the first 2 weeks of life, larvae already exhibit distinct behaviors such as spontaneous swimming and escape reflex. These traits, coupled with short generation times and high fecundity, make zebrafish ideal for high throughput studies of optogenetics.