SHORT VERSION of my REPLY: Why not?

Why? [Apologize for lengthiness]

Katherine,

naturally it will depend on the task and on some other parameters... Unfortunately you haven't defined YOUR real experimental settings at large.

but -

{admitting to have had no practical use or experience with HEPES-saline solutions ['buffer'] during my work-life, but nevertheless with "injections" of hypo-, normo-, as well as hypertonic salt solutions during my studies for PhD-thesis [rats, subcutaneous application of NaCl soln. into neck region] , and interested in many buffer recipes and the concept of using buffers}

- I don't have any evidence about adverse effects or well-founded reasons not to use HEPES-saline for injection in animal model(s):

First of all, HEPES Saline is / has been already used in molecular biology, cell cultures and flow cytometry....

QUOTE:

> END of QUOTE(s) (source: http://www.thermofisher.com )

There exist different recipes for HEPES-saline (e.g.: "simple" to more sophisticated:

>>

HEPES saline (2X)

50 mM HEPES

280 mM NaCl

To prepare the solution, dissolve 8.18 g of NaCl and 5.96 g of HEPES in 400 mL of H2O. Adjust pH to 7.10 with 0.5 M NaOH. Adjust the volume to 500 mL with H2O. Filter-sterilize. Store in aliquots at 4°C.

HEPES - Saline

Component M.W. mM amount/100 ml  

1. NaCl   58.44 154.0   900 mg

2. HEPES   238.8 10.0   238 mg

Adjust pH to 7.4 for use at 20 -22 C. (source: http://www.ansci.wisc.edu/jjp1/ansci_repro/lab/procedures/media/hepes_saline.html)

also: "POST Wed, 08/06/2008 - 13:10 by

Amar Annamalai: Please note the composition of HEPES saline,

HEPES 10mM; NaCl 151mM; KCl 4.7mM; CaCl2 2mM; MgCl2 1.2mM; glucose 7.8mM.

The pH of this solution should be adjusted to 7.4 using NaOH.

AMAR "

(source: https://www.scientistsolutions.com/forum/general-student-questions/urgent-composition-hepes-buffered-saline )

' We linked this to a corresponding item that is already on ResearchGate':

Article Catheter-Based Intramyocardial Delivery (NavX) of Adenovirus...

or even more sophisticated (for use with chelators like EGTA, EDTA, HEDTA, DPA, NTA, ADA) :

-----------------------------------------------------------------------------

DURHAM AC. 1983:

A survey of readily available chelators for buffering calcium ion concentrations in physiological solutions. in: Cell Calcium. 1983 Feb; 4(1) : 33-46. (sorry, PDF access only via PPV: https://www.sciencedirect.com/science/article/pii/0143416083900477?via%3Dihub

Abstract (only for convenience): Stability constants are reported for the binding of H+, Ca2+ and Mg2+ ions to the chelators commonly abbreviated EGTA, EDTA, HEDTA, DPA, NTA, ADA, and citrate, under uniform conditions of physiological temperature and ionic strength. Other compounds usable as calcium buffers are listed. The theoretical and practical considerations that influence the actual pCa attained in a chelator solution are discussed and a Hepes-buffered saline solution is suggested as a standard of "physiological pH". With these figures it is possible to make a rational choice of chelator to control the pCa and pMg of solutions for investigations in cell physiology, drug action, virus reproduction, and ion binding to proteins.

-----------------------------------------------------------------------------

In the separation of red blood cell fraction and platelet recovery (centrifugation):

Platelet Rich Plasma Prp From Mouse Blood (ESH-buffer):

EHS (EDTA-HEPES saline) 150 mM NaCl 10 mM HEPES, pH 7,6 1 mM EDTA

(Source: https://www.protocolpedia.com/blog/2017/05/10/platelet-rich-plasma-prp-from-mouse-blood/), cf. also:

1X Working Concentration Formula

Component M.W. Concentration (mg/L) mM

HEPES 238.3 300 1.26

Sodium Chloride 58.44 8,800 150

EDTA (Tetra- 452.2 452.2 1

sodium, Tetrahydrate)

Specifications:

pH: 7.0 - 7. 4

Form: Liquid

Shipping Conditions: Room Temperature

Expiration Date: 2 years from date of manufacture (source:

https://www.leinco.com/Substrate-and-Assay-Reagents/pdf/H1679.pdf

-----------------------------------------------------------------------------

HAGELBERG &ALLEN, 1990: Restricted diffusion of integral membrane proteins and polyphosphoinositides leads to their depletion in microvesicles released from human erythrocyte. Biochem.J.(1990)271,831-83 (source: https://pdfs.semanticscholar.org/a869/38ba651b2ee135412efbfc6df380073159a6.pdf)

-----------------------------------------------------------------------------

Hopefully this might be enough data for you encouriging you to (at least) try this approach....best wishes and regards, Wolfgang

Disclaimer: No affiliation to any of the mentioned dealers/companies. No financial interests.

I am highly convinced with what Prof Wolfgang suggested to you concerning HEPES buffer. It's versatile especially in cell culture experiments. I therefore recommend his contribution.

I am highly convinced with what Prof Wolfgang suggested to you concerning HEPES buffer. It's versatile especially in cell culture experiments. I therefore recommend his contribution.