E. coli Single-Strand DNA Binding Protein

What it means: DNA-Binding Proteins — the protein class this product belongs to.

Why it matters:

• It tells you what the protein does, so you can match it to your study.
• Proteins of the same class often share assay formats and readouts.
• The class helps you find related proteins and assay kits in the catalog.
• Knowing the class helps you plan suitable controls.
• It makes it easier to compare your results with published work.

For this product: DNA-Binding Proteins — Single-strand DNA-binding protein (SSB) binds single-stranded DNA, or single-stranded regions of double-stranded DNA, during DNA replication, recombination and repair; for example, DNA helicase unwinding creates single-strand DNA.

Tip: Use the matching ProFoldin protocols (under Documents) as a starting point for reaction conditions.

What it means: E. coli — the organism the enzyme or protein comes from.

Why it matters:

• SSB proteins from different organisms can differ in binding properties.
• Using the organism of your study keeps results relevant to that organism.
• Stating the organism makes your methods easy to report and repeat.
• The organism helps you choose the matching assay kit.
• Comparing SSB proteins from several organisms shows how conserved a binding behavior is.
• Results with one SSB do not always carry over to SSB proteins of other organisms.

For this product: Use this E. coli SSB in studies of E. coli DNA replication, recombination and repair.

Tip: Use the matching ProFoldin protocols (under Documents) as a starting point for reaction conditions.

What it means: 2 mg/ml — the concentration of the supplied stock.

Why it matters:

• The stock concentration decides how far you dilute the enzyme for each reaction.
• Knowing it helps you plan how many reactions one vial supports.
• Keeping the same final enzyme amount in every well keeps results comparable.
• It lets you compare your conditions with the matching kit protocol.
• A known stock value makes dilution steps easy to document.
• Keep the final enzyme concentration the same when you change the reaction volume, and check the linear range for your conditions.

For this product: Each vial holds 50 µl of 2 mg/ml E. coli single-strand DNA binding protein (100 µg) in 10 mM Tris-HCl, pH 7.5, 20% glycerol.

Tip: Dilute just before use, keep the protein on ice, and prepare only the amount needed for the day.

What it means: His-tag (N-terminal) — the fusion tag attached to the protein.

Why it matters:

• A tag lets you purify, capture or detect the protein with standard reagents.
• The tag position matters when it could affect binding or activity.
• Knowing the tag helps you choose compatible detection antibodies or resins.
• Tagged proteins can be pulled down to study binding partners.
• Stating the tag makes your methods easy to report and repeat.
• The tag adds to the molecular weight seen on a gel.
• If the tag is not needed downstream, plan controls that show it does not change the binding you measure.

For this product: His-tag (N-terminal) — the E. coli SSB in this product carries a His-tag at its N-terminus.

Tip: Consider the His-tag when you choose capture resins or detection antibodies.

What it means: 20.7 kDa — the molecular weight of one protein chain.

Why it matters:

• The molecular weight helps you confirm the protein on an SDS-PAGE gel.
• It lets you convert between mass and molar concentrations.
• Knowing the value helps you spot degradation products.
• It helps you plan gel percentages for the size range.
• Stating the value makes methods easy to report.
• For oligomers, the native complex is larger than one chain.
• Tags and other additions are part of the stated molecular weight, so compare it with gel bands accordingly.
• Knowing the value also helps you choose size-exclusion columns or filters.

For this product: One E. coli SSB chain with its His-tag is 20.7 kDa; E. coli SSB forms a homotetramer.

Tip: Use the 20.7 kDa value when converting mg/ml to molar concentrations.

What it means: Frozen — how the product is shipped.

Why it matters:

• Frozen shipping keeps the product cold during transport.
• Knowing the shipping condition helps you arrange for someone to receive and store the package.
• The product should be moved to cold storage as soon as it arrives.
• Checking the package on arrival helps you spot transport problems early.
• Planning storage space in advance avoids delays on delivery day.
• Frozen products should not be left at room temperature after delivery.

For this product: Frozen — the vial is shipped frozen; move it to cold storage as soon as it arrives.

Tip: Check the package on arrival, move the vial to cold storage right away, and contact us if it is not frozen.