Re: [ccp4bb] Seeding

- Protein crystallography

Main steps:

- Protein purification
- Crystallisation

Special:

- Programs for crystallography
- X-ray detectors

Basic tutorials:

   - Chemistry
   - Protein
   - Peptide
   - Amino Acids

Xtal community:

- CCP4BB

CCP4bb navigation

CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: Position available in Frankfurt
From: Tatsuya KAMINISHI kami {- at -} GSC {- dot -} RIKEN {- dot -} GO {- dot -} JP
Date: 2009-06-01

Next message:
Subject: Re: 3D LCD and glasses
From: "Bernhard C {- dot -} Lohkamp" bernhard {- at -} CHEM {- dot -} GLA {- dot -} AC {- dot -} UK
Date: 2009-06-02

Subject: Re: Seeding
From: vikas navratna vikasnavratna {- at -} GMAIL {- dot -} COM
Date: 2009-06-01

Dear HengChiat Tai

(a) According to me Seed Solutions should be stored depending on the
> stability of the crystals in the drop. If your crystal goes bad quite early
> then you have to make fresh seed frequently. Its always a good habit to make
> fresh seed, everytime you do streaking.
>
> (b) The number of drops which you can streak after dipping the whisker in
> seed solution once ! Depends on your swiftness. There are robots which can
> streak 12 drops continuously without the rquirement of washing in between. I
> can streak upto 6 drops continuously with a gap of less than a second. But
> it's always good to wash the whisker once in a while with water. If your
> crystallization condition has salts like Ammonium sulfate in it, then, the
> salt crystallizes quite fast on the whisker, as it is exposed to air for
> some time and you may land up seeding salt crystals in to your drop.
>
> (c)The inconsistency, which, you have been seeing in the crystal growth is
> quite common with streaking. Since it depends on how many micronuclei or
> seeds get in to the drop. Some times only one seed goes into the drop and
> you get a better quality single crystal in the entire drop. If two or three
> seeds go into the drop during streaking the effective protein concentation
> gets distribued between the seeds and as a result you have small and
> numerous crystals. The only solution to this can be " Streak as many drops
> as possible ".
>

>
> Your protocol for seed preparation looks fine.
>

> I think you can minimize the vortex steps. If possible vortex or mix it
> well with pipette.
>

> Choose those ends of the crystal for making seed solution which seem to
> be growing. It is like inoculating the Fresh media with bacteria which are
> in their early log phase of growth.
>

> Work with higher dilutions like, 100X and so on. Set up and streak as many
> drops as possible.
>

All the best

> Regards
>

> Vikas Navratna
>
> ------------------------------
> Hotmail® goes with you. Get it on your BlackBerry or iPhone.
>

CCP4bb navigation

CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: Position available in Frankfurt
From: Tatsuya KAMINISHI kami {- at -} GSC {- dot -} RIKEN {- dot -} GO {- dot -} JP
Date: 2009-06-01

Next message:
Subject: Re: 3D LCD and glasses
From: "Bernhard C {- dot -} Lohkamp" bernhard {- at -} CHEM {- dot -} GLA {- dot -} AC {- dot -} UK
Date: 2009-06-02