Sam Holtzen, PhD
@samholtzen.bsky.social
Pinned
Hi everyone! My name is Sam and I'm a postdoc at Caltech working on developing high throughput screening methods for metabolite biosensors! 🧪
I'll be posting some post threads soon on fundamentals of fluorescence, FRET, and biosensors! ✨
I'll be posting some post threads soon on fundamentals of fluorescence, FRET, and biosensors! ✨
Reposted by Sam Holtzen, PhD
Rare SCOTUS W
November 10, 2025 at 9:45 PM
Rare SCOTUS W
@notalawyer.bsky.social HAVE YOU SEEN IT youtu.be/-9CmFvGEXXk?...
ERIC ADAMS IS AN ICONIC GUEST | ZIWE INTERVIEW
YouTube video by Ziwe
youtu.be
November 8, 2025 at 2:09 AM
@notalawyer.bsky.social HAVE YOU SEEN IT youtu.be/-9CmFvGEXXk?...
Reposted by Sam Holtzen, PhD
Reposted by Sam Holtzen, PhD
whaaaaat how unexpected!
Gavin Newsom vetoes gender education bill, declines to sign other trans protections - buff.ly/MTUAV85
October 8, 2025 at 4:45 AM
whaaaaat how unexpected!
Reposted by Sam Holtzen, PhD
This analysis remains undefeated.
October 5, 2025 at 10:12 PM
This analysis remains undefeated.
hi science bluesky 🧪 i have a question. has anyone shown if sgRNAs are susceptible to degradation by RNases when they're bound to the Cas9 protein? I know they're very unstable when unbound, but I can't seem to find evidence of their stability in the RNP complex. any help is appreciated!!
October 1, 2025 at 8:32 PM
hi science bluesky 🧪 i have a question. has anyone shown if sgRNAs are susceptible to degradation by RNases when they're bound to the Cas9 protein? I know they're very unstable when unbound, but I can't seem to find evidence of their stability in the RNP complex. any help is appreciated!!
Reposted by Sam Holtzen, PhD
Hey remember when the CDC dropped 6 of the 8 foodborne illnesses from the nationwide monitoring system in July and one of them was listeria? Mentioning for no particular reason www.nbcnews.com/health/healt...
September 30, 2025 at 12:34 PM
Hey remember when the CDC dropped 6 of the 8 foodborne illnesses from the nationwide monitoring system in July and one of them was listeria? Mentioning for no particular reason www.nbcnews.com/health/healt...
Reposted by Sam Holtzen, PhD
An unprecedented violation of our civic and Constitutional traditions. Calling every military leader in the world back to the U.S. to hear a wildly inappropriate partisan campaign speech followed by a fascist call to use the military against Americans.
September 30, 2025 at 3:49 PM
An unprecedented violation of our civic and Constitutional traditions. Calling every military leader in the world back to the U.S. to hear a wildly inappropriate partisan campaign speech followed by a fascist call to use the military against Americans.
Reposted by Sam Holtzen, PhD
This is the official communication from the FDA to physicians on acetaminophen use in pregnancy.
- They acknowledge the lack of a causal link with autism
- Essentially tell physicians to keep doing what we've been doing anyway
It's very different from the press conference.
Pass it on.
- They acknowledge the lack of a causal link with autism
- Essentially tell physicians to keep doing what we've been doing anyway
It's very different from the press conference.
Pass it on.
September 25, 2025 at 1:59 PM
This is the official communication from the FDA to physicians on acetaminophen use in pregnancy.
- They acknowledge the lack of a causal link with autism
- Essentially tell physicians to keep doing what we've been doing anyway
It's very different from the press conference.
Pass it on.
- They acknowledge the lack of a causal link with autism
- Essentially tell physicians to keep doing what we've been doing anyway
It's very different from the press conference.
Pass it on.
Reposted by Sam Holtzen, PhD
Reminder: a large (2.5M+) sibling control study found "no evidence of increased risk of autism, ADHD, or intellectual disability associated with acetaminophen use". Precisely the kind of data that requires serious consideration before declaring mission accomplished.
jamanetwork.com/journals/jam...
jamanetwork.com/journals/jam...
Acetaminophen Use During Pregnancy and Children’s Risk of Autism, ADHD, and Intellectual Disability
This nationwide cohort study with sibling control analysis examines the association of acetaminophen use during pregnancy with children’s risk of autism, ADHD, and intellectual disability.
jamanetwork.com
September 22, 2025 at 9:03 PM
Reminder: a large (2.5M+) sibling control study found "no evidence of increased risk of autism, ADHD, or intellectual disability associated with acetaminophen use". Precisely the kind of data that requires serious consideration before declaring mission accomplished.
jamanetwork.com/journals/jam...
jamanetwork.com/journals/jam...
Reposted by Sam Holtzen, PhD
Universities. Rural hospitals. Tech companies. Several sectors are going to be profoundly hurt by this. Not to mention the chaos of the moment as current H1-B owners scramble to get back to the U.S., cancel travel, etc. due to the uncertainty. An absolute mess. As intended.
September 20, 2025 at 3:41 PM
Universities. Rural hospitals. Tech companies. Several sectors are going to be profoundly hurt by this. Not to mention the chaos of the moment as current H1-B owners scramble to get back to the U.S., cancel travel, etc. due to the uncertainty. An absolute mess. As intended.
Reposted by Sam Holtzen, PhD
the epistemic breakdown of factual reality in this political media environment has been so harmful
when facts genuinely favor the left, the right will simply deny the facts or call the messenger biased, without any refutation
reality will always be biased against a movement detached from reality
when facts genuinely favor the left, the right will simply deny the facts or call the messenger biased, without any refutation
reality will always be biased against a movement detached from reality
Political violence is evil, killing people is evil, a country with more guns in it than people is broken, and what the government is saying about political violence right now being a primarily leftwing phenomenon is factually, statistically untrue. They are using this moment to rewrite history.
September 16, 2025 at 3:09 AM
the epistemic breakdown of factual reality in this political media environment has been so harmful
when facts genuinely favor the left, the right will simply deny the facts or call the messenger biased, without any refutation
reality will always be biased against a movement detached from reality
when facts genuinely favor the left, the right will simply deny the facts or call the messenger biased, without any refutation
reality will always be biased against a movement detached from reality
Reposted by Sam Holtzen, PhD
We're witnessing the most aggressive, fanatical crackdown on free speech in my lifetime. The speed and breadth of government censorship and private sector and nonprofit capitulation has been astonishing. As has the lack of urgency/silence from people who've long claimed to care about this stuff.
September 15, 2025 at 12:30 PM
We're witnessing the most aggressive, fanatical crackdown on free speech in my lifetime. The speed and breadth of government censorship and private sector and nonprofit capitulation has been astonishing. As has the lack of urgency/silence from people who've long claimed to care about this stuff.
Reposted by Sam Holtzen, PhD
Political violence is abhorrent. I have not celebrated Kirk's death.
But Newsom calling for his followers to "continue Charlie Kirk's work," someone who praised stoning gay people as "god's perfect law," who called for men to "take care of" trans people like they did in the 50s and 60s, is not it.
But Newsom calling for his followers to "continue Charlie Kirk's work," someone who praised stoning gay people as "god's perfect law," who called for men to "take care of" trans people like they did in the 50s and 60s, is not it.
September 11, 2025 at 12:25 AM
Political violence is abhorrent. I have not celebrated Kirk's death.
But Newsom calling for his followers to "continue Charlie Kirk's work," someone who praised stoning gay people as "god's perfect law," who called for men to "take care of" trans people like they did in the 50s and 60s, is not it.
But Newsom calling for his followers to "continue Charlie Kirk's work," someone who praised stoning gay people as "god's perfect law," who called for men to "take care of" trans people like they did in the 50s and 60s, is not it.
Reposted by Sam Holtzen, PhD
Glenn Beck’s media outlet The Blaze just gave an interview last month to the person who killed the politicians in Minnesota
September 10, 2025 at 10:25 PM
Glenn Beck’s media outlet The Blaze just gave an interview last month to the person who killed the politicians in Minnesota
Reposted by Sam Holtzen, PhD
political violence is a terrible scourge that has claimed victims from both parties
the way some people are just itching to treat this as a reichstag fire moment to enable a dictatorship is extremely scary and a good reminder that political violence is a threat to the very core of liberal democracy
the way some people are just itching to treat this as a reichstag fire moment to enable a dictatorship is extremely scary and a good reminder that political violence is a threat to the very core of liberal democracy
Very, very bad stuff coming from leading right-wingers
September 10, 2025 at 9:14 PM
political violence is a terrible scourge that has claimed victims from both parties
the way some people are just itching to treat this as a reichstag fire moment to enable a dictatorship is extremely scary and a good reminder that political violence is a threat to the very core of liberal democracy
the way some people are just itching to treat this as a reichstag fire moment to enable a dictatorship is extremely scary and a good reminder that political violence is a threat to the very core of liberal democracy
Reposted by Sam Holtzen, PhD
Hot off the press: We can provide for the first time a systematic attribution of recent #heatwaves to the emissions of #carbon_majors. Essential new #Nature article coordinated by @yannquilcaille.bsky.social at @ethz.ch, with numerous contributors @usyseth.bsky.social:
www.nature.com/articles/s41...
www.nature.com/articles/s41...
www.nature.com
September 10, 2025 at 3:12 PM
Hot off the press: We can provide for the first time a systematic attribution of recent #heatwaves to the emissions of #carbon_majors. Essential new #Nature article coordinated by @yannquilcaille.bsky.social at @ethz.ch, with numerous contributors @usyseth.bsky.social:
www.nature.com/articles/s41...
www.nature.com/articles/s41...
Reposted by Sam Holtzen, PhD
Here is a word cloud of the words that were missing from the noncompetitive renewal awards but had been present in the parent award.
3/4
3/4
September 9, 2025 at 11:22 PM
Here is a word cloud of the words that were missing from the noncompetitive renewal awards but had been present in the parent award.
3/4
3/4
i remember seeing this chart in high school as a fun lesson"both sides are extreme, trust the center" and looking back now i grow weary
September 5, 2025 at 2:28 PM
i remember seeing this chart in high school as a fun lesson"both sides are extreme, trust the center" and looking back now i grow weary
Reposted by Sam Holtzen, PhD
one of the great conservative moves over the past decade has been to make themselves so unpleasant that their own family members are forced to cut them off, and then use that fact to argue that *liberals* are too uncivil
August 29, 2025 at 11:34 PM
one of the great conservative moves over the past decade has been to make themselves so unpleasant that their own family members are forced to cut them off, and then use that fact to argue that *liberals* are too uncivil
if you'd rather save face than run a successful country, you're not cut out for politics
Ship has sailed bitch www.bloomberg.com/news/article...
Bessent Warns of US ‘Embarrassment’ If Tariffs Ruled Illegal
Trump cabinet officials told a federal appeals court that ruling the president’s global tariffs illegal would seriously harm US foreign policy, with Treasury Secretary Scott Bessent warning of “danger...
www.bloomberg.com
August 29, 2025 at 9:14 PM
if you'd rather save face than run a successful country, you're not cut out for politics
Reposted by Sam Holtzen, PhD
I will remind folks those images of Nazi book burnings aren't burning just any books. They're burning the library of Magnus Hirschfeld; a gay, Jewish doctor who created an institute dedicated to LGBTQ sex education and healthcare. And a man who pioneered gender affirming care surgeries.
US government orders 46 states to destroy trans education materials
https://www.thepinknews.com/2025/08/27/trans-education-us-state-directive/?utm_content=1756312804&utm_medium=social&utm_source=bluesky
https://www.thepinknews.com/2025/08/27/trans-education-us-state-directive/?utm_content=1756312804&utm_medium=social&utm_source=bluesky
US government orders states to destroy trans education materials
The US government has ordered 46 states and territories to destroy education materials referencing trans people.
www.thepinknews.com
August 29, 2025 at 1:23 AM
I will remind folks those images of Nazi book burnings aren't burning just any books. They're burning the library of Magnus Hirschfeld; a gay, Jewish doctor who created an institute dedicated to LGBTQ sex education and healthcare. And a man who pioneered gender affirming care surgeries.